so it begins... 305 tpi to 350 build thread
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Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
so it begins... 305 tpi to 350 build thread
so after reading a bunch of threads on here i finally worked up the courage to dig in a start the tear down. my goal is to have a 300+hp car thats still fairly reliable. my emissions are up for the 88 cause its 25 years old so im not worried about that. here are the plans
-305 to 350tpi or lt1 setup.
-remove A/C
-remove smog pump
-remove a.i.r. system
-headers and xpipe exhaust system
-transmission gears upgraded? depening on budjet.
-tune the ecm
thats all i can think of for now. my budget is 2500 dollars and i want to be done by june. this is my first time doing an engine swap and to be honest im a little nervous. the only thing that really worries me is the wiring harness and the vaccume lines. i just dont really understand it. everything else im confident i can do. ill try and update my progress as i go and if i have any questions ill post them here too instead of starting new threads. heres my weeks progress so far.


hoods off, radiators out, a/c is half way out, battery is out, most of the harness is labled and out. thats about it for now. let me know what you guys think of that bad*** air intake
so far 2 questions have come up for me, #1 what is this thing? its right against the drivers side head lights. its hooked up to the T.B. and im pretty sure its some type of vaccume or breather tube? i just need an explination on what it is so i can better understand it.

#2 could you guys tell me what these relays are? i just want to lable them but i cant because i dont know what to lable them. lol.
this is the drivers side firewall...

this is right near the battery

any and all help is really appricated. suggestions are always nice too. just talking about it will give me some more confidence. hahaha.
-305 to 350tpi or lt1 setup.
-remove A/C
-remove smog pump
-remove a.i.r. system
-headers and xpipe exhaust system
-transmission gears upgraded? depening on budjet.
-tune the ecm
thats all i can think of for now. my budget is 2500 dollars and i want to be done by june. this is my first time doing an engine swap and to be honest im a little nervous. the only thing that really worries me is the wiring harness and the vaccume lines. i just dont really understand it. everything else im confident i can do. ill try and update my progress as i go and if i have any questions ill post them here too instead of starting new threads. heres my weeks progress so far.


hoods off, radiators out, a/c is half way out, battery is out, most of the harness is labled and out. thats about it for now. let me know what you guys think of that bad*** air intake
so far 2 questions have come up for me, #1 what is this thing? its right against the drivers side head lights. its hooked up to the T.B. and im pretty sure its some type of vaccume or breather tube? i just need an explination on what it is so i can better understand it.

#2 could you guys tell me what these relays are? i just want to lable them but i cant because i dont know what to lable them. lol.
this is the drivers side firewall...

this is right near the battery

any and all help is really appricated. suggestions are always nice too. just talking about it will give me some more confidence. hahaha.
Senior Member

Joined: Mar 2011
Posts: 668
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From: dothan, al
Car: 1988 pontiac trans am
Engine: None
Transmission: None
Axle/Gears: 10 Bolt
Re: so it begins... 305 tpi to 350 build thread
#1: the one on the top or right is the cruise control vacuum thing, the other round cylinder type object is vacuum storage or accumulator, i think. #2: I aint sure about the relays, I know one is for the bright lights, if you have a haynes repair manual, that should tell you. Goodluck on the build!
Thread Starter
Member
Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
#1: the one on the top or right is the cruise control vacuum thing, the other round cylinder type object is vacuum storage or accumulator, i think. #2: I aint sure about the relays, I know one is for the bright lights, if you have a haynes repair manual, that should tell you. Goodluck on the build!
and another thing i forgot to mention is i dont have an engine lift!!! if anyone has one and wants to get rid of it let me know!!! its kind of a must have if i want to do an engine swap. go figure

Joined: Mar 2000
Posts: 43,187
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Thread Starter
Member
Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
oh alright thanks. and one other thing, will my wiring harness work with an lt1? i read once that it will but im not sure. should i plan on buying a new harness?
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Joined: Aug 2010
Posts: 486
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From: MD
Car: 88 Iroc-z
Engine: ls1
Transmission: t56
Axle/Gears: 3.42
Re: so it begins... 305 tpi to 350 build thread
Bad *** air intake! Did it help any and dont you get worried about crap getting in? I.e. water, bugs?
Id go with a lt1 if you can. Better powerband and overall engine. Opti spark isnt that bad if you can get it working right. Some make it many many miles!
and im not sure about your wiring harness. I dont think you can swap it over though.
Id go with a lt1 if you can. Better powerband and overall engine. Opti spark isnt that bad if you can get it working right. Some make it many many miles!
and im not sure about your wiring harness. I dont think you can swap it over though.
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Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
made some good progress today, labeled some more wires, cut the exhaust out. i was able to loosen three of the four flange bolts out and got hung up on the last one cause the a-arm was in the way a little so i broke out the saws-all. man that stock exhaust pipe is thick!! i also disconnected the knock sensor and i noticed two other wires, one on each side of the block that were almost lined up with the spark plugs. one was disconnected and it looked like someone cut the wire and the other one was intact. i was just wondering what they were for if anyone knows. i messed around with the a/c too and its a real pain to pull off. its hard to find the screws that hold it in place and most of it seemed to be "glued" to the firewall. i read that i will have to invest in an a/c delete box too if i want to keep my heat....which i do. is that true? also, since im deleting my smog pulley and a/c pully i read that i will need a dummy pulley for one or the other because the water pump spins counter clockwise and there is no way to route the belt without one dummy pulley. is that true too? i know ive got a lot of questions here but its my first engine pull/swap so i just dont want to mess anything up. any advice is greatly appreciated. thanks!
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Thread Starter
Member
Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
Bad *** air intake! Did it help any and dont you get worried about crap getting in? I.e. water, bugs?
Id go with a lt1 if you can. Better powerband and overall engine. Opti spark isnt that bad if you can get it working right. Some make it many many miles!
and im not sure about your wiring harness. I dont think you can swap it over though.
Id go with a lt1 if you can. Better powerband and overall engine. Opti spark isnt that bad if you can get it working right. Some make it many many miles!
and im not sure about your wiring harness. I dont think you can swap it over though.
and yea actually i did notice some improvement in power. very slight tho. if i had to guess maybe 5-8hp? and i had air filters in the plastic intake thing that fits over the holes so i wasnt too worried about bugs or water. im gunna do it right though when i put my new engine in obviously. Thread Starter
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Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
made some more progress this weekend. pulled the engine and now im gunna start cleaning up the engine bay and trying to find a nice 350 to replace the 350. i think im just going to go with the 350 swap instead of the lt1. i really dont want to mess with the wires and from what ive read the tpi system is better on gas and is overall a good system so im just going to stay with it.






Thread Starter
Member
Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
http://www.hawksthirdgenparts.com/ca...mairboxes.aspx this makes me feel a little better about my "home depot special" and mine only cost 20 bucks!!
Joined: Mar 2000
Posts: 43,187
Likes: 45
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
I've never seen or heard that TPI gets better gas mileage than LT1. Of course, if you "utilize" the extra power the LT1 produces, you will use more gas.
Thread Starter
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Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
would this engine work? it says up to 86 but im pretty sure it would work fine right? http://www.ebay.com/itm/Chevy-Chevro...ht_1993wt_1163
Thread Starter
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Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
i forgot to clarify that what i read was comparing tbi to tpi. im sorry, i know im jumping around a lot im just not sure which direction i want to go. i will defiantly read the lt1 swap sticky before i make my final decision. thanks
Thread Starter
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Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
so i finally got my hands on a decent 350


cost me 500 bucks and apparently it only had 60k on it. i started the tear down yesterday and when i pulled the valve cover off one of my puchrods was just missing.... weird right? so i pulled the intake and heads off and it was no where to be found, he said it sat for about three years in his garage also. when i pulled the exhaust manifold off i found some accorns in them.
so im on the fence about weither or not i should do a re ring kit, replace the piston heads and crank as well. or just save the 300-400 bucks for the rest of my build. im trying to get 300-340hp to the wheels and ive got 1500 to do it as well as finish up all the odds and ends of the swap. what do you guys think?


i can still see the crosshatching on the cylinder walls so im assuming it has fairly low miles on it. (under 100k) but i really have no idea.


cost me 500 bucks and apparently it only had 60k on it. i started the tear down yesterday and when i pulled the valve cover off one of my puchrods was just missing.... weird right? so i pulled the intake and heads off and it was no where to be found, he said it sat for about three years in his garage also. when i pulled the exhaust manifold off i found some accorns in them.
so im on the fence about weither or not i should do a re ring kit, replace the piston heads and crank as well. or just save the 300-400 bucks for the rest of my build. im trying to get 300-340hp to the wheels and ive got 1500 to do it as well as finish up all the odds and ends of the swap. what do you guys think?


i can still see the crosshatching on the cylinder walls so im assuming it has fairly low miles on it. (under 100k) but i really have no idea.
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Joined: Mar 2011
Posts: 668
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From: dothan, al
Car: 1988 pontiac trans am
Engine: None
Transmission: None
Axle/Gears: 10 Bolt
Re: so it begins... 305 tpi to 350 build thread
I'd say get a complete engine rebuild kit. Here is one for 239$ http://www.summitracing.com/parts/FEM-MK6038A-000/ and then clean the block, pistons, rods and cranks and put it back together.
Senior Member

Joined: Mar 2011
Posts: 668
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From: dothan, al
Car: 1988 pontiac trans am
Engine: None
Transmission: None
Axle/Gears: 10 Bolt
Re: so it begins... 305 tpi to 350 build thread
Or you could bore it .30 over and get this kit http://www.summitracing.com/parts/FEM-CSMHP761-300/
Thread Starter
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Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
Yes I guess it's a good idea to rebuild it while it's apart. I would hate to get it all done an start it up only to realize it needs rings or I got a spun bearing. I'm not gunna have it hot tanked or bored over or anything like that but I am going to tear it down to the block an buy that first kit you showed me for 249 or however much it was. I also repainted my engine bay as well. It look pretty good for a rattle can job. I'll post picks tonight and I'm ordering that rebuild kit tonight too. I can't wait to start the rebuild!
Re: so it begins... 305 tpi to 350 build thread
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From: Readsboro, VT
Car: 85 IROC-Z / 88 GTA
Engine: 403 LSx (Pending) / 355 Tuned Port
Transmission: T56 Magnum (Pending) / T5
Axle/Gears: 3.42 / ?
Re: so it begins... 305 tpi to 350 build thread
the cross hatch on the cylinder walls tells me that the motor is probably in good, usable shape. I'd probably pull one main cap to look at the condition of the bearing, and as long as it looked ok, I'd put it back together and not worry about a rebuild for another 50k miles. Swap in a cam and whatever other mods you've got planned, and use it.
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Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
Oh cool! It would be nice to have someone doing the same swap in real time with me. I'm no expert but if you run into any issues let me know and I can at least tell you what I did and wheither or not it worked. I'd have to say the hardest pert was shelling out the cash for an engine I didn't even know ran. That and researching everything I need to do the swap and do it right. The farthest I've ever gotten in my engine was the intake manifold gasket. Everything past that is all new to me. It's a lot to learn but this site is invaluable. So much good informati
Re: so it begins... 305 tpi to 350 build thread
yea man im quite a bit behind you, my buddy has me a good motor with 1200 miles on it from a 89 GTA, complete with headers and everything, just im $200 short on cash, i should have it soon, the ONLY part im gettin confused on is the issues with a 305 computer, i have a 350 ecm but im hearing now i need the ESC module too?
Thread Starter
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Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
theyre slp runners. and theyre pretty much the only thing im keeping from the 305. im trying to get in contact with the guy that runs high flow fuel injection on facebook to get them ported as well as the plenum and manifold. from what i can see he does really good work.
Thread Starter
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Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
the cross hatch on the cylinder walls tells me that the motor is probably in good, usable shape. I'd probably pull one main cap to look at the condition of the bearing, and as long as it looked ok, I'd put it back together and not worry about a rebuild for another 50k miles. Swap in a cam and whatever other mods you've got planned, and use it.
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Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
so after some research ive narrowed it down to 3 cams,
http://www.lingenfelter.com/mm5/merc...Store_Code=LPE
http://www.summitracing.com/parts/NAL-10185071/
http://crane.carshopinc.com/product_...d/15861/104224
im leaning towards the zz4 because their seems to be a lot of room for improvements so this cam will compliment upgrades as i go along and its 100 dollars cheaper then the others. any thoughts? im sending my slp runners, stock intake and stock plenum to darin dochterman to be ported. check out his fb page http://www.facebook.com/pages/High-F...62540657151556 hes porting everything listed and cleaning them to look brand new for 450.00 (was 550.00 but hes giving me 100 of for my 305 intake runners plenum and TB) he said hes got feedback from customers that see 35 hp from the porting alone and 60+hp with bolt ons. im really excited to see how it comes out. i still need a 350 ecm and esu and there is no way im paying full price for them.....
http://www.lingenfelter.com/mm5/merc...Store_Code=LPE
http://www.summitracing.com/parts/NAL-10185071/
http://crane.carshopinc.com/product_...d/15861/104224
im leaning towards the zz4 because their seems to be a lot of room for improvements so this cam will compliment upgrades as i go along and its 100 dollars cheaper then the others. any thoughts? im sending my slp runners, stock intake and stock plenum to darin dochterman to be ported. check out his fb page http://www.facebook.com/pages/High-F...62540657151556 hes porting everything listed and cleaning them to look brand new for 450.00 (was 550.00 but hes giving me 100 of for my 305 intake runners plenum and TB) he said hes got feedback from customers that see 35 hp from the porting alone and 60+hp with bolt ons. im really excited to see how it comes out. i still need a 350 ecm and esu and there is no way im paying full price for them.....
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Joined: Mar 2010
Posts: 139
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From: slater sc
Car: 1989 camaro iroc
Engine: 350 tpi
Transmission: auto
Axle/Gears: 323
Re: so it begins... 305 tpi to 350 build thread
how did you fine a 350 tpi for$500.00. were i live everybody want 1000 to 1500.00 for them.
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Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
I searched and searched for like 2 months at local junkyards and the Internet. Finally found just what I was looking for on Craigslist. I was shocked too when I saw it. I contacted the guy the same day he posted it and bought it the next day. You just have to keep looking for deals they're out there.
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Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
finally got some time so i figured i would update my progress. i sprayed my engine block red and send out my intake manifold, plenum, and runners to be ported and cleaned up, i bought an AcDelco ESC for a 350 off ebay for 45 bucks, bought headman headers and y pipe off summit for about 300.00 and a mr. gasket dead soft aluminum gasket set for 35.00, i also spray painted my motor mounts and timing chain cover black and cleaned up my fuel rails and injectors too. its really coming along now. im a little nervous about the prom though. apparently i can get it running with a 350 prom but i will have to either burn a custom one myself which i have no idea how to do or find some one to do it for me. which also seems hard to find. ive got a little while to think about it though. i might just try to do it myself. bring on hours of reading and researching!! heres some pics of the progress.


and this is what i bought last night...
http://www.jegs.com/webapp/wcs/store...Term=760-66120
http://www.summitracing.com/parts/HED-68470
http://www.summitracing.com/parts/HED-17478
only problem with the y pipe is its a 2.5 inch outlet and the collector diameter is 3inch i think. i might have to have a custom pipe welded up to make up the difference. ill see when they get here


and this is what i bought last night...
http://www.jegs.com/webapp/wcs/store...Term=760-66120
http://www.summitracing.com/parts/HED-68470
http://www.summitracing.com/parts/HED-17478
only problem with the y pipe is its a 2.5 inch outlet and the collector diameter is 3inch i think. i might have to have a custom pipe welded up to make up the difference. ill see when they get here
Thread Starter
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Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
so the headers and y pipe came in along with my esc. im a little annoyed at the fact that the headers were painted black but they were only painted to prevent rust from building up during shipping and now i have to get all the paint off them if i want to hit them with some high temp paint. so thats my project for this weekend. ive got everything mocked up and i COMPLETELY forgot how the support bars/brackets attach to my belt drive assembly i know i have to keep some of the stock header bolts for them but i just dont know which ones i need. any help is greatly appreciated. or a picture would be invaluable. i definitely should have taken one before i took it off in the first place. im getting my intake back this week from high flow fuel injection too which im super excited for. he does AMAZING work. check out his facebook page when you get a chance. http://www.facebook.com/pages/High-F...62540657151556 his most recent pictures are all my intake being ported. hes doing the plenum runners and intake for 550.00 i think its a great deal for this caliber of work.
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Joined: Jun 2012
Posts: 25
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From: Cedar Rapids, IA
Car: 1986 Camaro Iroc-Z (sold)
Engine: 305 about to be 350
Transmission: full manual 700r4
Axle/Gears: auburn 3.42 limited slip
Re: so it begins... 305 tpi to 350 build thread
I gotta give you credit your more motivated than me. I've had my headers and x pipe for a week and haven't put them in yet lol. One of these days ill rip out the pooch 305 and do a proper 350. Ill definately check in to see how it goes though!
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Joined: Jul 2012
Posts: 2
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From: reading p.a
Car: 92 camaro rs
Engine: 350
Transmission: auto
Axle/Gears: idk
Re: so it begins... 305 tpi to 350 build thread
hey ppl i need a 305 engine and the wire harness for a 92 camaro..im new here so dont really know how to post my own things so please hit me backup
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Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: i need an engine
finally starting to look like something!!! just gotta track down the sensors that go into the heads, ( fan switch and temp sensor) and gasket match the ported runners and shes ready to drop in. i hope she starts!!! lol.
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Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: i need an engine
Some finished product pics and engine install. It went pretty smooth but I'm hung up on my injectors now. For some reason they all stay open the second I turn the key to the on position.




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Joined: Sep 2007
Posts: 244
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
Thanks guys. I finally got it running today!!!! Thank god. It's been 6 months in the making to get to this point and it feels great to get it running. It was my first swap so I pretty much learned everything as I went and I would deffinatly do it again. It feels great to build something with my hands and not go buy it from a dealer with dads credit card.
now I just have to put the Trans back in and weld up the o2 sencor and finish up the exhaust and I'm good to go! I should be running by the weekend!! I'll put a start up, idle, and maybe a quick burnout vid up soon
hahahaha I'll keep you guys posted!!
now I just have to put the Trans back in and weld up the o2 sencor and finish up the exhaust and I'm good to go! I should be running by the weekend!! I'll put a start up, idle, and maybe a quick burnout vid up soon
hahahaha I'll keep you guys posted!! Thread Starter
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Joined: Sep 2007
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From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: so it begins... 305 tpi to 350 build thread
Hahahaha oh I plan on it. I'm already lining up a new set of Mickey Thompson street ET's for when I burn the life off my current ones. What are you driving around here? Decent thirdgen a are few and far between around here. I've only seen one nicer then mine and that was at a car show. And thats not saying much because mines not that nice. Lol
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