Hi Mike,
Holley makes one like that in 4150, and one 4150 that is a "race" billet, but the Holley site does not tell you what the differences are.
Is yours 1:1 or progressive?
BR, Mark
Yes it does tell you the difference. The standard throttle body has progressive linkage and the levers for a Ford kickdown and that type stuff. The RACE throttle body flows exactly the same, but has an external linkage that is adjustable for either 1;1 or progressive. These are both cast and is the same throttle body housing and design used in NASCAR.
The billet throttle body is self explanatory....it's Billet.
The billet is of no benefit, unless you just WANT billet. My choice would be the "Race" throttle body, because of the linkage
