I bought my 67 RS Camaro a few years ago and it came with a brand new 350 SBC crate engine (GM 10067353). I know that it's a 260 Hp engine that needs some help. I'm trying to get this motor up to about 400 hp power if that is even possible. I have just removed the 76 cc cast iron heads off of it as well as the factory camshaft a few days ago. I replaced the 76 cc heads with Dart 127322 SHP Aluminum 64 cc heads with 200 cc intake runners. I also bought Comp Cams high energy aluminum die cast full roller rocker 1.6 to 1 ratio. I also have purchased a MPFI manifold which is based off the victor jr design with 32 lb/hr fuel injectors and a accufab throttle body which I plan to run with FAST EZ EFI computer system. I though about running a Fel Pro 1094 .015" steel head gasket or a Cometic .022" set of head gaskets. I'm estimating my compression to be 9 - maybe 9.5 to 1????

Side rant...... The car came with a brand new in the box Comp Cam XE 268H camshaft so I thought. The guy I bought the car from bought the camshaft new from an auto parts store near my house. Well mind you this is several years later I pull out the cam from the box which is brand new but it is not the comp cam it should be. I believe what happened is someone purchased the cam before the guy I bought it from, returned it with a 290 hp GM crate motor camshaft and the auto parts store did not catch it. So when my guy bought it he didn't know what to look for as did I. I called Comp and they said it's definitely not a Comp cam since it did not have any markings. I decided to take it over to my dads house who has a lathe and I put it in and checked the lobe lift and it came out to be exactly the same as the 290 hp GM crate motor cam. Mind you I did not check duration or any of that but it was enough to confirm that it definitely was not the correct cam. Anyways this brings me to my next question of what cam shaft I should buy I thought about just buying the same one Comp XE 268H. Open to suggestions.... I don't want a car that idles bad, had that before and did not care for it. Would prefer it had good low and mid response. Also like to try to get .500 lift with the 1.6 to 1 rockers because my news heads flow best at .500 lift. Also bought new Comp High Energy push rods because I was unsure if the factory push rods would work with guide plates. I plan on re using the hydraulic lifters because the motor has never been ran and they are brand new.

Thought about changing the pistons out for a set of Speed Pro Flat Top H345CP 4 VR 5 cc pistons to raise compression a little more if needed. Would rather not if I do not have to. I know just enough about engines to get myself in trouble. I know how to replace but not much about picking the right combination's. Any help would be appreciated.

By the way it's a brand new block never been ran, 4 bolt main, 2 piece rear main seal... Bore is 4.0, Stroke 3.48, Deck height appears to be .035 " when I checked it last night at TDC with my caliper. Piston are dished, I'm not sure what cc, Ive tried to cross reference the GM part number but no one has specs on the pistons. I assume they are 12 cc. Motor is rated at 8.5 to 1 with 76 cc heads but Chevy High Performance said it was more like 8 to 1.

I do realize it would have been easier to buy a short block or a completely different motor, but this is what the car came with and I'm trying to make it work. I tried to sell it and no one was interested so I decided to buy heads and go from there.

 

Good choice on the cam. The intake is .477 and the ex is .480, this is with a 1.5 rocker. With the 1.6 you will pick up about .030 on the lift. The EX-268 is one of the best cams for both power and torque. As for the pistons do not use the speed pro 345 because they will be about .040 down on the hole and will be worse for compression. Just use the shim head gasket .015 and the small chamber and you will be OK with pump gas. Sound like a good combination.

 

Thanks for the reply I found another Comp Cam I was thinking about trying. Its one of there cams for TPI. Close to the XE-268 but the lobe separation is farther apart. It's there Extreme Fuel Injection series. 260XFI H13 or the 268XFI H13. Both designed for tuned port injections with a chip. Should work with my multiport fuel injection? I'll give Comp a call monday and see what they think. Any other opinion is welcome. Thanks again.

 

Comp Cam XE 268 H has been ordered. Good on Comp Cams.... They gave me a good deal for being ex navy and because someone pulled a switcharoo. Good on them because they didn't have to do anything.