RE: distib shims from the V things.....
I had to raise the HEI in my 250 and found the V type HEI has a different sized neck where it fits into the hole. The solution was a trip to the local hardware store for a nylon washer that was the same OD as the collar of the HEI. Then simply open up the hole until it fit over the neck under the collar. A dremel tool worked fine. Deburr the slag that comes off and you have both a shim and the nylon is soft enough to be the gasket as well. This is the same material that oil pan drain plug gaskets are made from.
At this particular store the size I got came in 1/16 and 1/8 thickness. The 1/8 was what I needed.
Hope this might help someone else solve a shim problem. Mike
