pretty sure the 340 and 383 base plates are 3/8" in height diff. just traded with mike ross .. he was careful to be sure it was in fact a 340 plate I had ... the adapter looks like it is about 3/8" to me ? just a thought ..

When you say "base plates", I'll assume you mean the actual Shaker base/carb plate", and the adapter you saw? did you have it, or Mike Ross?


here's the Shaker base chart

Hi
Would be nice to have contact data to this gentleman who made this rods.
Thanks
Arne

Chris from Ny who used to make these rods sold his last one two years ago and has no plans to make more.
Try Tommy Chryco who advertises and contributes here.
He was talking about manufacturing a run of these.

Will have them available next month!

Very interesting information. I have a 383 base and never knew what the front hole was for.

That's awesome! I never could get a hold of the guy that made the 1st run of reproductions.

You have to wonder how rare of a part the factory original support rods are? I have never seen a factory original one on a car or at a swap meet.

The only original support I have seen was broken off in the block, bet that was common.

Scott at Harms Auto has the correct base spacer, which is not the 108-18 that Terry mentions. It is an aluminum one that was on all cars with a Holley 4bbl, in 1970 and 1971. It would have come with an asbestos top and bottom, which are not on Scott's spacer, as that type of material is no longer available. But he does have other suggestions for something comparable that would work the same as the asbestos.