Max-
Surprise Arizona is out in my neck of the woods. I could not find a local phone book or internet directory listing for Discount racing Engines or D.R.E.
My opinion: stick with your plan to buy the ZZ4. I used a ZZ4 shortblock with Edelbrock top end parts in my 69 and it is a fantastic engine. it makes 380 HP, over 400 Lb/Ft of torque, has a great choppy idle, and runs like a scalded dog (12.51 on BFG radial T/A's)
I'm a VERY experienced Corvette engine builder (5 years with GM, over 50 L98's, LT1's and LT4's and even an LT5 in that time) I've also designed and built about ten engines for my own and friend's cars over the past 15 years.
Here's why I would steer clear of the Ebay engine:
1) The 109 degree lobe separation angle of the cam is too tight for a street engine with power accessories. this cam would make very little vacuum, get HORRENDOUS gas mileage and would probably make your car's emissions too high. a street driven Corvette owner should cam their car with a lobe separation angle in the 112 degree range. this is the best compromise for power, emissions, and vacuum.
2) This engine has iron heads. it says they have been re-worked, but with all the great, high quality aluminum heads out there, your better off going aluminum. Aluminum allows you to run a higher compression engine (up to 10:1) without detonation (great for Corvettes). Aluminum also dissipates heat better than iron, so your cooling system doesn't work as hard (also great for Corvettes).
3) He says Federal Mogul flat top pistons, but he doesn't say whether they're cast, forged, or Hyperautectic. Hyperautectic pistons are most expensive, but they are worth every penny for durability's sake. the ZZ4 engine uses these. Forged pistons generate more heat, and cast pistons are too weak for the demands of RPM ranges above about 5000.
4) It says NOTHING about the crankshaft, which leads me to assume that it's cast, not forged. A small block Chevy that makes over 375 Lb/Ft of torque should have a forged crank for strength and durability.
Hope this helps. Good luck with your 75.
-Robert
