[RICK LAKE]

caprimaniac Any chance of getting a first name?
The supports for a T&D or Jesel setup need to be made from steel. These systems will turn 10,000 rpms. You have a couple of issues between the two. Aluminum weaker than steel, Aluminum more exspansion rate than steel, strength again goes to steel. Shorter life than steel with fatigue.
Aluminum is cheaper and lighter and could be used on system where a rpm limit of 7,000 rpms is done, but again how many heat cycles are the limit??
There are a couple of articles in HotRod,Car Craft, Hot Rodding, and race motor manuals that show you the correct geometery for the rockers to valve stem. As for custom pushrods, Smith does the quickest and best job for correct length needed. As far as going to 3/8 pushrods, make sure the rod clears the adjust location and doesn't hit the back side of the rocker. Make sure the opening in the head is large enough for clearance through the whole cycle of each pushrod. 3/8" has less defection than 5/16". You might want to look into tapered pushrods. If you are going to still do 8,000 rpm hits, 3/8" will hold up better but may endup with having to control more weight. Good luck. Didn't jesel have a light weight shaft setup of windsor motors? I thought they machine a "I" groove into the top of the rocker to remove weight. Rick L.