Carb'd Vortec Upgrades

[Doppleganger]

Just picked up a free 97 Vortec 350, complete sans intake. Heads are uncracked and I've been offered good $$$ for them by a circle track guy who said they aren't allowed to use aluminum heads so these are in demand. I have the budget to get some GOOD aluminum upgraded heads, pistons, roller cam, etc. Just looking for ideas on what you all have used with intake-heads-cam pairing and what works well. I think 400hp is very doable.

Every build I see is either FI with a roller cam or carb with a flat tappet. I'm going carb (for now) with the aforementioned upgrades.

TIA

 

[75gmck25]

I used the Blueprint aluminum heads and purchased them from Summit. That improved flow and with thin head gaskets brought compression up to an estimated 9.4. I also used a Howards retrofit roller cam, since I did not have a factory roller block. I am using an Edelbrock Performer and stock Quadrajet, but still have iron exhaust manifolds and duals. My estimate is that I'm probably in the 325 HP range due to limitations from the exhaust and a cam duration of 213/217 @ .050. However, it has a great power band for a work truck.

350 HP is very easy to realize, but for 400 HP you might have to work a little harder. Assuming you get good flowing aluminum heads first, you need about a 750-850 CFM carburetor, a good intake (similar to an Edelbrock RPM should be okay), headers, 2 1/2" dual exhaust, and a cam that will get you the HP. I assume the cam needs a duration of about 230-240 @ .050, and with that duration it will have a high power band. However, you can run one of the cam simulation programs to verify the HP and peak RPM.

If you want to keep a good low end you will probably need a high stall torque converter to get RPM up into the power band quickly. A K20 may already have decent rear end gear ratio, but if it doesn't you probably want 3.73 or 4.10 gears with stock 31" tires. Bigger tires will need even lower gears.

Bruce

 

[Doppleganger]

That sounds great - thanks much for the info.

I've used alot of Cometic MLS HG's over the years. I guess I need to find out what the stock thickness on a SBC is and how much thinner I could go. On other cars I did, stock was .045 and we used (usually) a .036....even down to a .028. Bumped the CR up about 1 - 1.5 and motors that used to be ping ****** ran great on 87. I have heard that a 9.5CR is about as high as one would want to go on a SBC before requiring premium fuel. Not a big deal now but would be if/when it goes way up again.

Thanks again!

 

[C10MixMaster]

Just picked up a free 97 Vortec 350, complete sans intake. Heads are uncracked and I've been offered good $$$ for them by a circle track guy who said they aren't allowed to use aluminum heads so these are in demand. I have the budget to get some GOOD aluminum upgraded heads, pistons, roller cam, etc. Just looking for ideas on what you all have used with intake-heads-cam pairing and what works well. I think 400hp is very doable.

Every build I see is either FI with a roller cam or carb with a flat tappet. I'm going carb (for now) with the aforementioned upgrades.

TIA

I have been working on putting together a new motor for my truck to. comp cams has a listing of dyno runs and the key components used to get there. heres the link https://www.compcams.com/dyno-graphs unless the drag strip is where your gonna run your truck you might consider going for torque. 400+ torque is pretty easy to accomplish and it helps get these big trucks moving.