How can I get more power from a 428CJ?

[Dwight]

a lot of good suggests.

I think a basic tune up, the correct timing, correct jetting and correct air cleaner could yield a few hp.

I worked on a 351W last fall that had 2 previous owner with 11,000 miles on the car. The third (new) owner wanted me to do a few maintenance items. I drove the Cobra for 20 miles or so to get the feel of it. Ran good but would not rev above 4300 rpms in any gear. I removed the 8" S&H air cleaner and it would go to 6000. 11,000 miles and no one noticed it would not run above 4300 rpms?????
Changed the carb, corrected the jetting. Picked up a few ponies and then he decided he wanted 500 hp.
Called Keith Craft and ordered a 408 with 530 hp.
We also changed the mufflers to Classic Chamber 3".
I never did see what that Cobra had with the new motor, tires, trannie, etc. but I think it's very fast.
And Mike drives like an old lady. But he very happy with his new Cobra.


My suggestion is that if you want 100 more hp call Keith and see what heads and a cam to match would cost. You will gain the most hp from that.

and DanEC advice is basic to any changes you want to make.

Dwight