polishing up the 305
#1
Senior Member
Thread Starter
iTrader: (1)
Join Date: Jun 2009
Location: N.E. Ohio
Posts: 564
Likes: 0
Received 0 Likes
on
0 Posts
Car: 87 Gta
Engine: 5.3
Transmission: 4l60e
Axle/Gears: 3.42
polishing up the 305
Hey guys, before we get someone fighting about just building a 350, the idea is just to help out my tired 305 out a bit. It was my first car and I still unfortunately .. I mean fortunately have her. I don't want to dump money into it because hey its a 305. My Gta is in the middle of my turbo swap. And I have some extra things from summit and cash from the scrap. Anyways I was thinking a nice thumpr cam upgrade the valvetrain to handle maybe deck down the heads, port and polish my self. Match my intake to the heads. It does have a new intake and dis. Just back from when it was my dd from school. Any ideas or suggestions would be cool. Try to keep it cheaper bc A. It's a 305 B. It's probably going to be the gf's car she gets to drive
#2
Supreme Member
iTrader: (1)
Join Date: Mar 2007
Location: Arlington, Tx
Posts: 3,525
Likes: 0
Received 6 Likes
on
5 Posts
Car: 91 Camaro RS
Engine: empty bay (for now)
Transmission: Built T-56
Axle/Gears: 3.42 stock posi disc
Re: polishing up the 305
tbi, or tpi? if its tbi, switch to a better set of heads.
#3
Supreme Member
iTrader: (1)
Join Date: Mar 2007
Location: Arlington, Tx
Posts: 3,525
Likes: 0
Received 6 Likes
on
5 Posts
Car: 91 Camaro RS
Engine: empty bay (for now)
Transmission: Built T-56
Axle/Gears: 3.42 stock posi disc
Re: polishing up the 305
but youre on the right track. boost the compression a little and put a better cam in there. also if you havent touched the exhaust you need to. stock exhaust will kill any upgrades you do.
#4
Senior Member
Thread Starter
iTrader: (1)
Join Date: Jun 2009
Location: N.E. Ohio
Posts: 564
Likes: 0
Received 0 Likes
on
0 Posts
Car: 87 Gta
Engine: 5.3
Transmission: 4l60e
Axle/Gears: 3.42
Re: polishing up the 305
Yea I have a set of headers, it was originally an 89 formy with a tbi. I think they're summit shorties but what the hey.
#5
Supreme Member
iTrader: (1)
Join Date: Mar 2007
Location: Arlington, Tx
Posts: 3,525
Likes: 0
Received 6 Likes
on
5 Posts
Car: 91 Camaro RS
Engine: empty bay (for now)
Transmission: Built T-56
Axle/Gears: 3.42 stock posi disc
Re: polishing up the 305
shorties with a good y pipe are better than stock. if it was tbi, then you have some junk heads. i wouldnt waste money on getting any work done on them. is it carbed now?
#6
Supreme Member
iTrader: (1)
Join Date: Mar 2007
Location: Arlington, Tx
Posts: 3,525
Likes: 0
Received 6 Likes
on
5 Posts
Car: 91 Camaro RS
Engine: empty bay (for now)
Transmission: Built T-56
Axle/Gears: 3.42 stock posi disc
Re: polishing up the 305
if you can get youre hands on a set of 58cc vortecs, that would be youre best bet, they run better than pretty much any stock gm head. theres a set right now in the classifieds for $150
#7
Senior Member
Thread Starter
iTrader: (1)
Join Date: Jun 2009
Location: N.E. Ohio
Posts: 564
Likes: 0
Received 0 Likes
on
0 Posts
Car: 87 Gta
Engine: 5.3
Transmission: 4l60e
Axle/Gears: 3.42
Re: polishing up the 305
Ya that was my next question, upgrade to a set of 350 heads and or any set of vortecs
Trending Topics
#8
Senior Member
Thread Starter
iTrader: (1)
Join Date: Jun 2009
Location: N.E. Ohio
Posts: 564
Likes: 0
Received 0 Likes
on
0 Posts
Car: 87 Gta
Engine: 5.3
Transmission: 4l60e
Axle/Gears: 3.42
Re: polishing up the 305
And yes it has a carb now. To many junk sensors, and a bad CPU with no dealer or jy options
#9
Supreme Member
iTrader: (1)
Join Date: Mar 2007
Location: Arlington, Tx
Posts: 3,525
Likes: 0
Received 6 Likes
on
5 Posts
Car: 91 Camaro RS
Engine: empty bay (for now)
Transmission: Built T-56
Axle/Gears: 3.42 stock posi disc
Re: polishing up the 305
if its carbed, then a set of 305 vortecs with a nice cam and freeflowing exhaust will be a good boost. the 350 vortecs would lower your compression so stick with the 305 versions with the 58cc. no need to really make any mods to the head, unless you wanna up the compression. then you can just run a .025" compressed gasket instead of the normal over the shelf .043" gasket and not mill the heads.
#10
Supreme Member
iTrader: (1)
Join Date: Mar 2007
Location: Arlington, Tx
Posts: 3,525
Likes: 0
Received 6 Likes
on
5 Posts
Car: 91 Camaro RS
Engine: empty bay (for now)
Transmission: Built T-56
Axle/Gears: 3.42 stock posi disc
Re: polishing up the 305
you will however need a new intake to run the vortecs, but you can find a used for for around $100-$200. so for around say $500 you can have a stronger running 305.
#11
Senior Member
Thread Starter
iTrader: (1)
Join Date: Jun 2009
Location: N.E. Ohio
Posts: 564
Likes: 0
Received 0 Likes
on
0 Posts
Car: 87 Gta
Engine: 5.3
Transmission: 4l60e
Axle/Gears: 3.42
Re: polishing up the 305
Yea that's why I tried to stay away from the vortecs, but around here people throw away 305 parts including Vortec heads. Thanks for the info though
#12
Senior Member
Thread Starter
iTrader: (1)
Join Date: Jun 2009
Location: N.E. Ohio
Posts: 564
Likes: 0
Received 0 Likes
on
0 Posts
Car: 87 Gta
Engine: 5.3
Transmission: 4l60e
Axle/Gears: 3.42
Re: polishing up the 305
If I do decide to go this way, got an idea on another good set of heads? Is much rather not get rid of my brand new intake just to get one to fit the vortecs
#13
Supreme Member
iTrader: (1)
Join Date: Mar 2007
Location: Arlington, Tx
Posts: 3,525
Likes: 0
Received 6 Likes
on
5 Posts
Car: 91 Camaro RS
Engine: empty bay (for now)
Transmission: Built T-56
Axle/Gears: 3.42 stock posi disc
Re: polishing up the 305
305 tpi heads. no matter what heads you wanna go with, you wanna stick with the smaller chamber size or youll lower your compression and loose power. unless you want to stick some domed pistons in with the larger CC head to bring the compression back up. but its not really worth tearing into the botom end of the 305.
#14
Senior Member
Thread Starter
iTrader: (1)
Join Date: Jun 2009
Location: N.E. Ohio
Posts: 564
Likes: 0
Received 0 Likes
on
0 Posts
Car: 87 Gta
Engine: 5.3
Transmission: 4l60e
Axle/Gears: 3.42
Re: polishing up the 305
Nope, just looking for something to play with/beat on then ill end up parting. I was just wondering what would be a good set, I know mine are junk plus need valve seals Haha. Is like to raise compression w.o spending a bunch . I'm thinking maybe a thumpr cam tho
#15
Supreme Member
iTrader: (1)
Join Date: Mar 2007
Location: Arlington, Tx
Posts: 3,525
Likes: 0
Received 6 Likes
on
5 Posts
Car: 91 Camaro RS
Engine: empty bay (for now)
Transmission: Built T-56
Axle/Gears: 3.42 stock posi disc
Re: polishing up the 305
those thumper cams are garbage. all they do is make the engine sound aggressive, not actually BE agressive.
#16
Senior Member
Join Date: Jun 2011
Location: Detroit, MI
Posts: 939
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1987 IROC-Z red t-top
Engine: Nothing much
Transmission: I wish t56
Axle/Gears: 9bolt 3.27 4sale
Re: polishing up the 305
your GF car well try not to buy any part new, shorty headers y pipe flows out back, LB9 heads if u can port them taller rear end and some roller rockers get a 9bolt rear end the like 200 or so, shift kit she will be on yeer *** running bout 13.7. and the best free mod clean the car out no need for extra w8 take the spare out running a 20+ year old tire u will just be back a L7 one
#17
Senior Member
Thread Starter
iTrader: (1)
Join Date: Jun 2009
Location: N.E. Ohio
Posts: 564
Likes: 0
Received 0 Likes
on
0 Posts
Car: 87 Gta
Engine: 5.3
Transmission: 4l60e
Axle/Gears: 3.42
Re: polishing up the 305
Rlly? I was just at summit picking things up for the Gta, asked what would be a decent cam around the .500 lift mark. Said the thumpr cams are pretty good but it already has a shift kit and I don't plan on putting anything else on it besides a little bit of motor work.
#18
Supreme Member
iTrader: (1)
Join Date: Mar 2007
Location: Arlington, Tx
Posts: 3,525
Likes: 0
Received 6 Likes
on
5 Posts
Car: 91 Camaro RS
Engine: empty bay (for now)
Transmission: Built T-56
Axle/Gears: 3.42 stock posi disc
Re: polishing up the 305
ive never used one, so i dont have first hand experience, but i have yet to meet someone whos happy with the perf gain from a thumpr cam.
#19
Senior Member
Thread Starter
iTrader: (1)
Join Date: Jun 2009
Location: N.E. Ohio
Posts: 564
Likes: 0
Received 0 Likes
on
0 Posts
Car: 87 Gta
Engine: 5.3
Transmission: 4l60e
Axle/Gears: 3.42
Re: polishing up the 305
Youre probably right on that tho. As I am stepping up from a stock cam Its gotta give me something. Any suggestions on that? I'm sure I can find a set of 305 heads around here maybe get lucky on a set of vortecs and a intake. Is rather not spend a lot though. As this is my beater.
#20
Supreme Member
iTrader: (1)
Join Date: Mar 2007
Location: Arlington, Tx
Posts: 3,525
Likes: 0
Received 6 Likes
on
5 Posts
Car: 91 Camaro RS
Engine: empty bay (for now)
Transmission: Built T-56
Axle/Gears: 3.42 stock posi disc
Re: polishing up the 305
if youre not going for the best engine you can,just an upgrade, then a set of heads off a tpi 305 will be fine. can probably find a set at a jyard for cheap and no need for a new intake
#21
Senior Member
Thread Starter
iTrader: (1)
Join Date: Jun 2009
Location: N.E. Ohio
Posts: 564
Likes: 0
Received 0 Likes
on
0 Posts
Car: 87 Gta
Engine: 5.3
Transmission: 4l60e
Axle/Gears: 3.42
Re: polishing up the 305
Nah my Gta has all the money in her.. plus I was dumb and decided a TT build... But anyways I'm not trying to make a race car outta this one but is like it to actually have a little bit of ***** if ya know what I mean. That's why I came to you guys.
Thread
Thread Starter
Forum
Replies
Last Post
Hotrodboba400
Firebirds for Sale
3
12-10-2019 07:07 PM