My ongoing project is a 74 El Camino that I've had for about a year. Gone thru brakes, wheel bearings, all new suspension & steering, interior up to wife's standards etc... Now that I know nothing is going to fall off I'm looking at getting more out of the 454 engine:
Block: 3999289, 10305CWH, heads 336781 GM9T Pass, stock intake, new Edelbrock 1407 Carb, new HEI Ignition, mildly bashed in headers. Runs well but hits the wall at 4,000 rpm. My research indicates this engine came out of a 73 Impala and listed at 215 HP (feels like it sometimes). Impala had a TH400 trany behind it, but I have a Muncie M21 in Elco.
I would like to get this thing up to 425-450 HP without having to get into the bottom of the engine. Can anyone give me some advice on how to get there efficiently ? I'm a pretty competent parts changer, but not having done this before may overlook some of the finer detail points that really make a difference. At this point I'm considering:
Edelbrock 2161 intake
Timing chain & cam, (desktop Dyno says 276/286 & .5 lift)
I have a spare set of 781 heads from a 73 SS I could have worked over (increase valves to 2.19/1.88 & shave a bit ?) (incidentally these are Pass-X not Pass whats the difference ?),
I also have a set of unbashed headers to put on.
Other Ideas ??

Thanks Mike

Hi Mike,welcome to Team Chevelle :)
Lots of great 454 build info in the performance and engines forums :thumbsup:

I would think you need to increase the compression to get more performance and make use of the heads and cam. New pistons with a slight dome to bring it up to 9.6:1 or a bit more.

Look to the basics to wake it up:
1. Headers and exhaust
2. New intake
3. New Cam (with correct valve train)
4. 781s with larger valves

Don't think you need to work bottom end here to get what you're looking for. Follow Mr.4speeds advice and do a search in performance section. Lots of low-buck 454 advice there.
Oh, and welcome to the best Chevelle and Elcamino site on the net!!!!