So I am trying to figure out what the difference is between the 502HT and the ZZ502?? THe HT is only 5k and the zz is about 7.5k. The only difference I see is the cam and maby the heads?? IT seems like you could get the HT and throw some 049 heads (or a head of your choice) on it and a bigger roller cam and have a engine that performs just as good or better then the zz.....

The 'HT' (High Torque) series of engines are intended as replacement upgrade unit for vehicles already equiped with that style of engine - so this is really intended as a BB replacement for many 366~502 engines in earlier trucks etc...
It is a High Torque engine - not specifically a performance assembly, as is the ZZ unit.
The compression ratio is much lower - mid 8's I think v.s mid 9's for the ZZ's.
The aluminum Heads of the ZZ allow higher CR than the Iron headed HO & HT engines.
The HO engines are a good choice, if you're looking to save some money for a performance base AND you already have an intake, carb and the other parts not included.
The ZZ series of engines is really a good bang-for-the-buck! These engines are, for all practical purposes, shipped complete - the intake, carb, dist, water pump and other parts are installed or shipped with them - so you don't have to buy them = $$$ saved... These added parts, plus the better flowing/bigger valved Aluminum heads, plus the additional 'good performance parts' inside these engines more than make up the price differencial, if you're looking for good reliable BB power in a box.
The $1,400~1,600 for the ZZ is well spent :thumbsup:

As always JMHO's;
John

I second that. If you want to feel empowered and build your own I would recommend the ZZ502 short block and rectangular port heads (500 cubes is the break even point on the oval vs. rectangular debate) and a strong roller (I would go solid, though there are many good hydraulic grinds just be sure to verify they fit GEN VI blocks). A single plane manifold and MSD ignition with 2" primary headers and you will be always be asking for tires for Christmas, your birthday, anniversary, ….


Larger Dave