I was lucky enough to have a customer bring me a 472 Hemi crate engine last September to confirm its health (dyno) and then make it the way he wanted it. When rebuilding or reconfiguring an engine I LOVE it when I have a running specimen to dyno test as the BEFORE baseline. Longstory short the crate Hemi lived up to its ratings and made exactly 535 hp and some 550 torque in its as delivered state.

The customer initially wanted 600HP or better and I was all game but when we got down to brass tacks I didn't think that was realistic. This Hemi is slated for a 'Cuda with a Shaker hood with power brakes, and air conditioning and ultra reliable. It is to be driven to all events/shows etc... So that ruled out the single plane manifold, big solid roller cam and higher compression. I also couldn't go nuts with the budget. The customer and I settled on 550hp + as a goal once he saw how small the cam was. 242 @ .050 .530" before last 238 @ .050 .504" before lash on a 112 LSa.

We settled on checking the shortblock out, some headwork, cam change and manifold/carb change. I didn't like how the crate hydraulic flat tappet cam gave up well before 6000rpm and solid rollers just aren't reliable if you aren't on top of them all the time--so I went with a custom Comp solid flat-tappet with the nitriding and Howards EDM solid lifters. Head work consisted of bowl blending, guide profiling, and crisper valvejob. The crappy M1 dual plane was replaced with an Indy Arlen Vanke dual plane in order to work with the Shaker. Hemi's just don't look right with one carb unless its a 4500 so on went a 950 Ultra XP 4500 series.

Breakin was something of a stressful nightmarish event as I had a flat tappet failure earlier this summer and pulling the valvecovers 6 times on a Hemi is no fun. I'm also super paranoid about rear main leaks on big Mopars .

After breakin it was time to make an exploratory pull. Was I ever happy with how this engine turned out. No smoke, no leaks, no bad noises, lash didn't move more than a thou, and more power, and better looking. We ended the test session with 580 hp and 580 tq with a much nicer rpm'ing Hemi--Isn't that what they are known for? I am starting to see why so many people like the 2G Hemi. J.Rob