Crate engines have really made upgrading our Camaros easy. Grab a keyboard, or pick up a phone if you roll old school, and in a few days, a big ol' crate will show up full of mechanical goodness. It couldn't be any easier. The downside is that, compared to a custom engine, you may not get exactly what you want. GM Performance Parts (GMPP) must have understood this when developing its line of ZZ502 big-block engines. Sure, you can order both basic and deluxe engines fully assembled (PN 19201332 deluxe) and ready to rock, but for those who like to spin a wrench and save money, there's another option: the ZZ502 kit (PN 1231171 deluxe). Like it's fully assembled cousins, the ZZ502 in kit form comes in both basic and deluxe versions. If you want it all, including starter, water pump, spark plugs, plug wires, distributor, carb, and everything else needed, then go with the deluxe kit for the simple reason that it beats hunting around for stuff, and you'll be assured it's designed to work together. Getting the engine in kit form also has two other benefits. First, you'll save right around $400. We don't know about you but, for the few hours it will take to assemble the engine, that's a pretty decent savings. Secondly, it's perfect for the gearhead who wants to add a bit more performance to GM's already-potent package.

We were curious what a couple of upgrades would do for the big-inch big-block in terms of power. Now, we didn't want to tear into the short-block since it came fully assembled, but cleaning up the as-cast aluminum heads seemed like a logical place to grab a bit more power. We also thought the GM cam specs seemed a bit on the tame side, so sliding in a bigger bumpstick was another easy path to better performance. In addition we decided to ditch the one part on the crate engine that we weren't thrilled with-the stamped steel rockers. Swapping over to a roller rocker would increase power, reliability, and if we stuck with the same ratio, we wouldn't even have to buy new pushrods. Best of all, we already had $400 extra in our wallet to put toward these upgrades. With a pile of parts and a few ideas, we headed over to Don Lee Auto in Rancho Cucamonga, California. Owner Tim Lee isn't a television repairman, but he's still got this ultimate set of tools.

Head Games
Packaged in the ZZ502 kit was a set of aluminum oval-port heads with 2.25-inch stainless intake valves, 1.88-inch stainless exhaust valves, 290cc runner volume, and 110cc combustion chambers. Good heads, but like all "as cast" cylinder heads, they can benefit for a little massage therapy. For this we took them to Tim's Porting in Santa Clarita, California.

Lift Intake After
.200 138 149
.300 193 218
.400 233 278
.500 272 306
.600 299 331
.700 318 347
.800 327 359
.200 119 122
.300 145 153
.400 168 170
.500 189 187
.600 202 201
.700 210 216
.800 230 226