Fast 78/78
#3
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
#6
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.
#7
Good pictures of porting to 85mm and info on the intake in this thread.
https://ls1tech.com/forums/generatio...85-pics-2.html
https://ls1tech.com/forums/generatio...85-pics-2.html