i have a 88 formula firebird with a 305 tbi lo3 i just bought the car not to long ago and it sit for 8 years befor i got my hands on it. it ran well for a little bit but started using oil and ticking soon after so i pulled the motor and started looking for another i bought a 350 tbi out of a 88 chevy 4x4 truck that was pulled and rebuilt the guy had planes to put it in hes street stock but noticed after the rebuild that it didnt have the on the block hook up for a fuel pump that is a must on a race car so i bought it dirt cheap only the has lost the intake and throttle body off of it so i was wondering if mine off my 305 would work on it with out any troubles and also if there was any thing i should know about wile doing this swap for example problems with ecm or wiring fuel pump pressure etc.. just any thing i should know about wile doing this swap or if it is just going to be a easy swap with nothing need to be changed wich would be great news. thanks for any heads up or help you may be able to offer.

never done this before but i would think that it would be just like swaping another 305 into it

 

matter of fact, i went through that about 2yrs ago. i put a 69 vette motor in my birb. used everything top end of original 305. yes, even the intake and throttle body. worked perfect. no problems at all. but suggestion, that 350 is going to have to breathe a lil more so i would get shorty headers and a half way descent exhaust system. JUST MY OPPINION

 

thanks tatlounge just what i was hoping to hear makes me feel more comfortable doing this and i bought a set of shortys that i was going to put on my 305 just never got around to it so ill just put them on the 350 and the car came with a cat back flowmaster system so i think that should work just fine i cant wait to get her running again thanks again

 

oh yeah and cant a muffler shop make me a y pipe for the headers and also is it very expensive to have them do this if so couse im straped for cash and the y pipe for my car was like 200 bucks so i was thinking a muffler shop would be cheaper

 

Im sure they can make one but dont know how much it'll cost. if they make one for you though, your stock, or an aftermarket exhaust system might not fit on your car.

 

i was reading a thread on here that my stock 305 throttle body wont work on my 350 that i would have to change the injectors is this true if so would it be easyer just to switch to carb

 

now i keep reading somthing about my ecm that i would have to tune it for the 350 or it wont run right is this true if so how do i do this cause i really dont have the money to put a carb and intake on the motor so i would like to just swap my tbi setup if it not going to be a big hassel please help i need to get this thing going asap its my only car

 

if you didnt do much to the cam in the 350, the tbi will work just fine. it does in my 92 bird.

 

they can, but i used to work at midas in ohio and it is more expensive for a shop to do this than to go to summit and buy the edelbrock y pipe for shorty headers. i think its around $150-160 . works great though and sounds nicer

 

good thanks for all the help got the 305 out so im going to start puting the 350 in tomorrow i dont think its had any thing big done to it just a stock rebuild but not for sure i didnt do it a friend did. so ill have to ask

 

I think you only have to change the injectors if you did a 350 swap with higher flowing heads. more airflow would make it run lean.

Im not sure but I also think cam upgrades on a 350 with 305 injectors would also make it run lean.

You would have to either buy an ecm from a thirdgen that was running a 350 or burn a new chip.

This is from my primitive thirdgen knowledge, you might want to wait for someone to confirm

 

It would have to be a B-body (Caprice, etc.) or truck, because there was no 350 TBI in f-bodies.

 

well ive talked to a few people who have done it and said it ran fine and some say they had to swap ecm. i started putting the 350 together today and should have it ready to start sometime tomorrow so i guess ill see how it runs then ill post up whem im done and let every one know if i need to replace the ecm if so i might just go with a carb on it cause i just love the lope sound you can get out of the carba any how thanks guys for all the info i really appreciate all the help

 

well hit a small problem today that set me back a day the flywheel from the truck on the 350 was a in bigger the the one from the 305 and after pulling the tranny i found the my flywheel wash cracked in like three places. so im going to pick up a new one tomorrow and hopfully drop the motor buy tomorrow night. i cant wait i miss driving the car already and its only been like six days lol

 

well got the fly wheel on an bolted up the tranny but when i was putting the motor on fount the oil filter hit my headers and the fram so ordered a adapter to day it will be in tuesday put it on shim mthe starterand im ready to rumble (i hope)

 

Which headers do you have?

 

Another question

I kept the intake manifold from my LO3.

Which manifold is better of the 2? The LO3 or LO5?

 

not shure boght them really cheap the but buy shape and apperance i think there flowtechs

 

ok ive hit another wall here i but a new fly wheel on the three fifty it was a 12.86 in the one that came off was a 14 in got the motor in and all hooked up the starter in gauges but is so tight a fit it gets stuck on the flywheel and i have to use a hammer to back it off tryed shimming it dosnt help still does it i dont know what to do now any advise

 

oh yeah and the starter is for the 305 case the one that came out for the truck was for a 14in flywheel not 13 so i figured it wouldnt work but as ive said befor im no car wiz just learning as i go

 

Oops, sorry I posted this in the wrong thread. Didnt mean to hijack

 

any body help me here i need to get this thing going

 

So let me get this straight. you are using the starter from the LO3 and you have a different size flywheel than that starter was used with origanally?

 

no origenal size flywheel and started from the lo3 now on a 350 still dont have the problem fixed

 

i did not finish reading but i just did this same thing. had a 305 got a 350 from jasper. the new motor melted my ecm. its to much for a stock 305tbi computer even with an aftermarket chip. im staying with the 305 computer for now and getting a chip from a 92 caprice with the 350 tbi and upgrade your injectors and fuel pump. i got 65lbs/hr injectors for mine. in fact im not done yet. i will let you know whats up when im done

 

well im pretty well finished (finaly) it was really not that bad of a swap to do but like any swap there was a few here and there problems. flywheel and starter problem was not a problem with the flywheel or starter. the rocker arms where tightned down so far the valves would not open wich was putting every thing in a bind. so make sure if you have some one rebuild a motor for you its atleast some one with some common since. lol i used the origenal intake and throttle body and the origanil whole pully system. the original ecm for the 305 and the original distributer. the loop system is now gone becase i put headers on the 350. i havnt really had a chance to really get on it yet beacause it is a new motor and im giving it a little break in time but i have had no problems with the fuel pressure the infectors or any thing at all it runs like its a factory done job the check engin light isnt even on wich was a shock to me because i figured taking out the loop system and the cat a other things it would of kicked. if any problems do accour with the ecm or any thing ill be sure to post up and let every one know and if in a few weeks still no problems ill post that as weel to let you know everything works good. thanks to everyone with the help they have offered for me alot of it came in really handy all i can say is if you have a third gen car this you deffinatly need to be part of this site.

 

hey man thats great. Im in the middle of my 350 swap but I lost my job so its literally sitting on the hoist half way in the car.

A buddy is going to give me his v-belt set up for free so once I get that I can get the engine in and running but I still need a new 350tbi ecu and injectors.

Its great to know the swap worked out for you with the 305 ecu... did you swap out injectors also?

 

if your asking me. yes. i had to find 65lbs hr injetors from somewher in B.F.E cost me 70 a piece. but you need them. i caught my computer on fire cause it was trying to hard. also im upgrading my fuel pump.

 

Couldn't you have just pulled some stock 350 injectors from the yard and shoved em in your pocket? I figured since I got my motor from a suburban, Im going to get my injectors and computer from a suburban. Dont know if this'll work but im sure I can get a chip flashed to solve the problem

 

i dont know what the deal is for some people but mine is still running fine and ive gave her all she had the other day and didnt miss a lick still running like a champ and i used my injectors and all off the 305 i whent to orilleys to get a set of 350 injectors and the 305 and 350 where the exact same injector i dont know if this is just for the truck my 350 origanlly came out of or what but it used the same intake throttle body and all no difference even the ecm is the same ive had no problems at all out of it like i said in another post you couldnt even tell that it was a swap runs just as good as it did out of the factory (but with more power!) i dont know if it would be different for you or if it matters what the motor came out of but my part numbers where all the same and same psi injectors and all. good luck with the swap hope it goes as well for you as it did me cause i was on a budget to and there is no way i could afford to replace the injectors throttle body or ecm but if i would of it would of been the same parts that came off my 305.