mikemunoz

I got a fast 78 intake with a fast 78 tb, was wondering if i can put a 90mm tb on my fast 78 intake, would it fit. need info asap thanks

98silvermaro

iTrader: (8)

If its a 3 bolt TB it will fit BUT its not going to help you any because of the 78mm intake

mikemunoz

i read that porting the opening and just putting a 90mm tb works but just making sure. plus also read porting the runners and opening and you got yourself a basic 90mm intake. an i wrong

98silvermaro

iTrader: (8)

you can port it out some but it wont port out to a 90mm opening and the runners wont open up that much either

garygnu

most 90 mm TB I know of are 4 bolt design .

wicknewman

iTrader: (13)

The largest a FAST 78 opening can be ported is 85mm. Any larger and you will not have area left for a gasket sealing surface between the TB and intake. Even when ported to the 85mm size you need to do some minor mods to get the gasket to seal properly. The 78 is identical to 90 in runner design and internal area. Only difference between the 78 and 90 is the opening.

wicknewman

iTrader: (13)

Good pictures of porting to 85mm and info on the intake in this thread.

https://ls1tech.com/forums/generatio...85-pics-2.html

bayer-z28

iTrader: (14)

That would almost be the same question as "Can I fit a 90mm TB on my LS6 intake?" No.. You can do an 85mm TB but it will need an adaptor.