Just interested in why you need/want a tranny with more than 6 speeds with a 4BT? What are you planning on doing with it?I'm looking for a transmission with more that 6 gears, I saw in another thread (http://www.4btswaps.com/forum/showthread.php?t=1064&highlight=spicer)that someone used a RoadRanger RTO-6610 or RTO-610 10 Speed. And that the trans weighs about 357lbs.What would I need to adapted that transmission to the 4bt?
With the equivalent of 1.5 Allison Transmissions (350+ lbs) and a 4BT(Big Block). Your total weight is going to be in the neighborhood of #7500lbs. 105hp is barely going to push that, and it's going to be even slower(Dangerously slow) with the kind of load to justify that big of a transmission. The 6BT would be a better bet in that sort of rig. If 3.9L diesels were practical they'd put that size engine in from the Factory for towing83 Chevy K30 Crew Cab Dually