Stabilizing heads

[tubman]

Most commercially available heads these days have bolt holes that are bigger than 7/16" (some are as large as 1/2"). When I put the heads on my last build, I could literally move them around on the block when all the bolts were in but not tightened. I did not think this was a good situation, so I decided to find a way to take care of this problem. Of course, in a perfect world we would all live in New York and plan ahead enough to send our components to "GOSFAST"s shop and get alignment pins a installed to solve this, but I am 1500 miles away and already down the road with this build. Here's how I have attempted to solve this problem.

I procured some 1/2" OD .030 wall aluminum tubing. This results in a tube with an inside diameter of .440" (remember, 7/16" is .4375). I then bored the bolt holes between the cylinder pairs out to 1/2" (one set of heads I did were already at this dimension). The heads are 1.840 thick at these bolt holes. Since the compressed gaskets were around .055", I cut lengths of the tubing off at 1.870. I also beveled the end of the tubing.

I then put some long guide studs I made into the block and installed the head over these. I the ran the tubing pieces over the guide studs with the beveled side down. When I wiggled the head and gasket enough, I could feel the bevel on the end of the tube slide into the bolt hole in the gasket. After this, I put a couple of more bolts through the head into the block to secure it, removed the studs, and inserted a couple of bolts (using the special hardened steel washers I DID get from Gary).

The result is a head that does not move on the block. I used ths procedure on the 255" Merc I did for my '51 club coupe and everything worked out well. The attached pictures are from doing this same procedure on the 258" hot rod engine I am just finishing.