Dyno 356 cam Extreme build!

joshua. c.

Active Member
this thread has been very educational and interesting so far. any new updates on your builds? have you run the new head with the extreme cam yet? id be interested to see the results.


Well-Known Member
I'd like to hear it myself. :thumbsup:

I had an OHH65 briefly that I considered modding, but was put off by the head design. Had I known about the head swap potential, I might have kept it.
fistfullabar,he hasn't been on here for a while. I don't think he as done anything with it. think he has been working on his gto and other stuff.
I still have my head, if time permits I would like to start building my stroker ohh BIG Bore motor with that head I found....
Not sure what happened to him. He was going to buy an OHH65 shroud and some other stuff from me around when he left. I never got the check. Hope he's alright.
The decision to use OHH valves resulted in other challengees. They are quite a bit longer than the valves in the OVRM heads, but the plus was I could use OHH pushrods. The OHH are much bigger and beefier than the OVRM pushrods. The longer valves created the condition having too much little of and install height to having way too much.

This also of course completely changed the height of the rocker shaft.

To make this work, I had to machine billet aluminum valve spacers to achieve the correct .900" install height and I had to machine a new yoke for the rocker shaft system. When I made the yoke, I moved the bolt holes to the correct spacing and moved the fulcrum shaft forward .030" to center the rocker over the valve. This was a lot of trial and error, but I eventually ended up with the perfect geometry.

Here's pics of the spacers and the yoke that I machined for the rockers.

What was your experience with the champion rocker arms...
BamAss5150 I think the only problem he thought maybe he was getting with the rockers where trying to maybe mushroom the tip of the valves. i have not posted anything yet on my OVRM HEAD BUILD. but i did find some valve lash caps that will might work on this project.
number is a dyno part# EXF-LASHCAP and is also listed as CV LASH CAP found this under the briggs stuff.
something that tecumseh power might want to look into before actually running it hard.