Welcome to CHR:

We’re a knowledgeable and rather outspoken bunch here but a lot of good information can be had! I love El Caminos – and the 64 is certainly a sweet ride. As to your engine build, a few suggestions:

“Chevy 291 heads with studs and guide plates, 202/160 valves, 67cc combustion chambers, CompCams 981-16 valve springs.” – I would not use these heads for several reasons not least of which is that they’re 50 years old and unless they’re perfect, you could be bolting up trouble. To the best of my knowledge, the pre 1970 factory cast iron performance heads (461, 462, and 291) were all 64-cc. These heads made decent power but were developed for leaded fuel. Unleaded fuel requires the valve seats be replaced with hardened valve seat inserts or they wear the valve seats very quickly. I would recommend Vortecs if you want to stay with cast iron or better yet, some aluminum heads.

The ComCam springs are pretty stiff for street type applications using stock rocker arms. I would select a roller cam and go with springs having seat pressure of 120-145 pounds and open pressure in the 330-350 pound range.

“Edelbrock 7101 Performer Intake” Use a Performer RPM or a Weiand Street Warrior 8125

“What would be a good cam to run? I was looking at Comp Cams XE268H or XE274H?” Neither. Both are flat tappet cams and you should go with a roller cam. Can’t make a recommendation here until you calculate your static compression ratio. Hopefully you’re between 9:1 and 10:1. Don’t exceed 10:1 and expect to run pump gas successfully.

“200R4 transmission” – be prepared to drive in 3rd all the time (except on the freeway) – especially with 3:36 gears. Go with a three speed (TH350/400) automatic.

Regards,
Glenn