Not too sure about the rules of the old appendix J (group N) but i was lead to believe that you needed to use the old style twin SU manifold & not allowd to take metal out, but can add metal ??? (i`ve been out of that scene for some time now so rules have probly changed somewhat)... I like setting these things up on the late 4 bolt style twin carb manifold but highly modified my own (my dad`s) way,,, they`re pretty dam spectacular when done well & i havn`t managed to better that set up with a weber/dellorto -->yet. Dam heck, i even ran a "SINGLE" SU on my alloy V8 powered VW Kombie Ute & the dam thing was so good it could wheelstand away, yet idle along happilly at 200rpms in the soft boggy beach sand,,, only have to ask all the Turbo charged datsun boys about all their SUs & see what they say. very hard to beat the good old SU.
most times when people fit a weber/dellorto & find improvement is when the old SU package wasn`t (or most probabl;y wasn`t) set up well in the first place & you`ll get the same stories from people swapping back from a weber to an SU (or pair of them) from the same type of problem where the weber was poorly set up & the SU(s) replacement was set up well.
I also like them both tho, but it`s a matter of "Horses for courses", i prefer the twin 1" & 3/4SUs on my roady as it gives me heaps of grunt & plenty of hi speed flow yet quiet & economical when needed/wanted
I run the weber for the speedway mini simply for the sake of ease & simplicity.
But i`m leaning more & more to the injection side of things these days so carbs to me are becoming "old hat" even tho i still love em
They`re all easy, cheap & simple tho --->compared to injection,,,i`ve been mucking around for ages now with injection & starting to think that i shouldn`t have bothered, but we are actually getting somewhere with it all now, just painfully slow progress doing it all myself without the use of a dyno (YET)
when i`ve got this all a bit better & i`ll have learnt a hell of a lot more along the way, then i`ll hit the dyno & see what we have & what more we can do.
whew!!!,,,ok i`m goin back to work
