Closed Chamber Heads

[stevehayes01]

So I am starting to plan out the Big Block build out for the truck and had some things I wanted to get opinions on.

Truck as it sits.....
Semi-recently Rebuilt 454 MKIV(less than 30K on it)
Rebuilt 3 speed trans
G80 Locker
Magnaflow Highflow cat
Magnaflow 24" muffler
3" pipe Cat Back

So this is the build plan I am looking at so far....

1. Comp Cam (something mild)
2. Edelbrock 3764 Performer 454 TBI Intake Manifold
3. Exhaust ---Single pipe and no headers yet (I live in Cali so headers for CARB are too expensive right now)
4. Adjustable FPR
5. Stage 1 Chip ( I will tune it)
6. Open air intake
7. New Distributor....looking at an MSD
8. Cylinder Heads........????


So my question on heads that I am on the fence about is the heads... Right now its got Peanut port stock heads and I am debating on swapping to closed port heads to bump compression up some (roughly 9:1 would be target). Also what is involved in getting Vortec heads to work?

So looking at a set of 3964290 closed port heads but not sure yet.
3964290 1969-70 454 Closed 345, 360, 390 LS-5 100.9cc


So really looking for some feedback and suggestions on the build plan and some experience with different head choices. Thanks in advance.

[Busted Knuckles]

Your 290 castings are semi-closed, they'll breathe a lot better than true closed chamber or L-29 Vortec. Your choke is the intake...you'll find that the GM and Edelbrock have smaller ports than the heads. If you're going to step up to large ovals, you'll need to upgrade the intake as well. Ideally, your ports start large (at the intake) and gradually get smaller (close to the valve) to increase velocity. When you go from a small port intake to a larger port head, you kill the velocity.
What's feeding it - a throttle body or carb?
You'll make more power with a good breathing head and lower compression than with a mediocre breathing head and higher compression.