I have the original 283 from my 64 Malibu that I am trying to get down the track faster. The block is original, no boring done, yet. After reading several articles and posts, I decided that I needed to upgrade the came and put a pair of heads on. Here's my problem:

I had stock everything, except for a single-plane alluminum intake with a Holley 600, and an HEI system. I ran with a 4:11 posi behind a 350 auto. Life was good.

Then I bought a set of "High Velocity" heads, 58cc, 1.94s. I also replaced the stock cam with a new .447/.447, new lifters, push rods, etc. I also went with a dual-plane intake with a Quadrajet on top, from advice taken from my brother-in-law. The result - I lost .5 sec in the 1/8 mile.

Please explain!

Disclaimer: I will not replace my 283 with a 350, 383, or anything else. The point here is to run what I own and make it as fast as it can go. That, to me, is the fun of racing. Besides, I bought this car when I was 13 for $175. That was 20 years ago. I'm not about to change the motor.