I asked for more specific information because diagnosing a problem from distance is an iffy proposition at best.

Personally, it sounds like you have a mismatched engine parts combination (if you have been fighting this problem for 6 years, I suspect you have covered the simple basics several times by now).

The problem could be any number of things from compression ratio (to low?) to intake ( trying to use a single plane intake with large runners) to carb (too big/too small), to heads ( Chamber size producing too much/too little compression, extensively ported, too big or too small valve size), to carburator (too big/too small correctly jetted?) to cam (it has to match the rest of the componets, AND has to be timed properly) to exhaust (it sounds like that may be plugged, and I would correct that first before I did anything). You transmission and rear end ratio sound pretty good, but what is the stall speed on the converter, and does it match the RPM range on the engine.

If you have a mismatched combination and put a new engine in but use the same mismatched componets (i.e. intake, carb exhaust etc) you will have the same problems you have now.

Now personally, from the RPM range and type of driving you indicate you are doing I'd concentrate on torque and let the HP numbers take care of themselves.

The combination I'd recommend building is:

8.75 to 9.1 compression,
Stock 1.94 heads
Cam in the 4.50-4.80 lift range with around 2.80-2.90 duration
(flat tappet cam, maybe a littler hotter on a roller)
A free flowing exhaust (good rams horn type manifolds, or if going with headers no bigger than 1 5/8 primary tube size)
A dual plane intake with reasonably small runners and a carb in the 600-650 CFM range.
A stock HEI giving about 36 degree total advance at about 2800 RPM shoud be a good starting point for the iginition.


It's not a real glamorus combination of parts, but it is proven and works very well.