Procomp aluminum cylinder heads on my 496 BBC

I just wanted to share my experiences with these heads so others can evaluate what I dealt with and decide if they are worth their investment. So in April this year I ordered from Skip White his BBC aluminum heads. They are Procomp heads. These things, as plenty of you know, are sold a lot of places and under a number of different names. Born and bred in the Good Ole US of A Peoples Republic of China. They are so cheap I thought it was worth the risk. So here is my first hand experience with them.

They arrived and looked pretty good. Skip White really isn’t to blame as their company has good customer service and was really helpful with all the stuff I bought. They seemed to do good machine work on everything that arrived at my shop.

They showed up loaded with valves and springs. As we started to disassemble them just to go over them once, the first thing we discovered was that the spring pressure was way to high for what I was building. That was easy to fix. But the next thing we discovered was this:

If you look closely in the upper left hand corner of the intake runners you will see that the bare metal disappears under the gasket. Note also that the bolt holes are correctly aligned. As much bare metal as you see in the lower right hand corner is as much as they are offset up under the gasket in the upper left hand corner. I know that trimming gaskets isn’t that uncommon but this seemed surprising to me in this day and age of CNC machining. Especially because the Edelbrock air-gap intake I am using matched up very well to the gasket. We proceeded to match the ports to the gasket spending more than I was expecting to clean it all up. But, so far so good.

When I started assembling the heads I encountered one or two rockers that sat funny on the stud. I struggled to get the pushrod guides to hold the rods over far enough to line up nicely. And, as luck would have it, one of the rods kinda interfered with the passage way through the head. Back to the machine shop.

Now I am finally bundling it all up. Everything lines up and feels ok. Putting a little oomph on the intake manifold bolts (mind you not much) by hand and all of a sudden one of the bolts starts freely spinning. Brand new set of heads and the first time I run the intake bold into the hold it strips the threads. Checking the holes out and there aren’t helicoils in them. Not that it surprises me maybe as these aren’t crazy torqued holes. But still hand tight and they spin??

With luck on my side they were blind holes. So I was able to helicoil them myself in place without disassembling everything.

I know that all heads need a little massaging before assembly. But these kind of blew me away. I haven’t even fired the engine yet and I’m basically in the same price range as a new set of AFR’s. Lesson learned I guess.

So all that being said, I ended up setting these head aside and starting over with something I can trust. I ordered Brodix heads. I’ll get that updated later.