First time engine build, need some advice on a combo
Thread Starter
Joined: Oct 2001
Posts: 646
Likes: 1
From: Sedalia, MO
Car: 1991 Z28 convertible
Engine: 305 TPI
Transmission: TH-700R4
Axle/Gears: 3.73 posi 4th gen 10-bolt
First time engine build, need some advice on a combo
I have an 88 GTA that currently has a 305 TPI out of an 85 IROC in it...so no roller cam. I will be pulling the engine in a couple weeks to freshen it up with new gaskets, as well as repainting it. I have also decided that I will be ditching the TPI and going with a carb setup. Here is what I have:
-305 TPI out of 85 IROC
-non-roller cam
-0416 castings, all stock, rebuilt about 30k mi ago (will probably do that again while I have them off)
-aluminum hypereutectic flat top pistons (engine was rebuilt about 30k mi ago)
-stock bottm end
-Car has 3.27 posi rear gears
Car also has a world class BW T-5.
Today, after reading the tech article here on switching from TPI to carb, I got a Holley 4 barrel 600 CFM carb from my neighbor. Looks really clean, may look into rebuilding and cleaning it up. It has a manual choke.
I'm also wanting about putting in a new cam but there are a lot of different ones out there. I'm looking for a cam that will give a noticeable lumpy idle. If I have to change the valve springs, I will when I get the heads tanked and the valve seals replaced.
For intake, what intake would work good with what I have, and with whatever cam y'all recommend?
I would like something in the neighborhood of 300 hp when all is said and done. I am willing to do some porting to the heads if that will help me reach that goal.
This is my first time doing this, and my first time working with a carb. I am eager and excited to learn! Any help or guidance will be appreciated.
On that note, a 350 build isn't an option due to funds right now, I'm doing this on a budget, whichever intake I get I will try and find a used one, ebay has a ton of used aftermarket intakes for the SBC.
-305 TPI out of 85 IROC
-non-roller cam
-0416 castings, all stock, rebuilt about 30k mi ago (will probably do that again while I have them off)
-aluminum hypereutectic flat top pistons (engine was rebuilt about 30k mi ago)
-stock bottm end
-Car has 3.27 posi rear gears
Car also has a world class BW T-5.
Today, after reading the tech article here on switching from TPI to carb, I got a Holley 4 barrel 600 CFM carb from my neighbor. Looks really clean, may look into rebuilding and cleaning it up. It has a manual choke.
I'm also wanting about putting in a new cam but there are a lot of different ones out there. I'm looking for a cam that will give a noticeable lumpy idle. If I have to change the valve springs, I will when I get the heads tanked and the valve seals replaced.
For intake, what intake would work good with what I have, and with whatever cam y'all recommend?
I would like something in the neighborhood of 300 hp when all is said and done. I am willing to do some porting to the heads if that will help me reach that goal.
This is my first time doing this, and my first time working with a carb. I am eager and excited to learn! Any help or guidance will be appreciated.
On that note, a 350 build isn't an option due to funds right now, I'm doing this on a budget, whichever intake I get I will try and find a used one, ebay has a ton of used aftermarket intakes for the SBC.
Thread Starter
Joined: Oct 2001
Posts: 646
Likes: 1
From: Sedalia, MO
Car: 1991 Z28 convertible
Engine: 305 TPI
Transmission: TH-700R4
Axle/Gears: 3.73 posi 4th gen 10-bolt
Re: First time engine build, need some advice on a combo
OK, since I'm not getting any responses, how about just posting some of the mild 305 combos you all are running to give me ideas?
Senior Member
Joined: Oct 2004
Posts: 965
Likes: 2
From: SE, Ohio
Car: '86 Z28, '91 RS
Engine: 305ci, 305ci
Transmission: TH200c (no kidding), TH700r4
Axle/Gears: 2.73, 2.73
Re: First time engine build, need some advice on a combo
Do not ditch the TPI that is money wasted and going in the wrong direction. Why would you replace the new, better tech, with old cave-man tech?
Here's some interesting reading for you. Fast355 built a 305TPI that was a vortec roller block with ported vortec 305 heads. Dyno @ 356rwhp. Good read there. https://www.thirdgen.org/forums/tpi/...tpi-310-a.html
Also those 416 heads are decent in stock form and great ported with larger valves. If you search you can find some flow data in both forms. I'm porting a set right now, it's the second set of these heads i've done. They are meaty in all the right places and are a dime a dozen. So if you do mess up it's easy to replace them.
Theres a copy of an article from one of the car mags where they built a 305 using 416 heads, ported with large valves, that produced great HP. Check it out; http://www.hioutput.com/tech/343hp/343hp.html
Here's some interesting reading for you. Fast355 built a 305TPI that was a vortec roller block with ported vortec 305 heads. Dyno @ 356rwhp. Good read there. https://www.thirdgen.org/forums/tpi/...tpi-310-a.html
Also those 416 heads are decent in stock form and great ported with larger valves. If you search you can find some flow data in both forms. I'm porting a set right now, it's the second set of these heads i've done. They are meaty in all the right places and are a dime a dozen. So if you do mess up it's easy to replace them.
Theres a copy of an article from one of the car mags where they built a 305 using 416 heads, ported with large valves, that produced great HP. Check it out; http://www.hioutput.com/tech/343hp/343hp.html
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