good gearbox choice

[HK1837]

I'd just use a 390 4 barrell Holley. You don't really want triples with factory air? I assume you are talking HQ-WB here?

Use an M20 4spd with a 3.08 or 3.36 diff. Don't use an M21 behind a 6cyl in a big heavy van - you'll hate it!

[JackHopkins]

i dont have factory air yet, but i have a set of triple sus at home, i was just wondering if they would both fit in. and yes its in a hj van. what would maek an m21 so bad? and as there a huge a difference between a 3.08 and 3.36