4bt vrs 6bt

[EColeman]

I've seen it mentioned that obviously a 4bt is 33% smaller than a 6bt but I don't know if anyone else has made these observations.

4bt 33%less than 6bt

CI238 359

HP105 160

TQ265 400

I thought it was interesting that the numbers were almost exactly 33% less (+-1) I just got an 86' 4bt that I'm pretty sure has a H1C/18cm egh housing which is probly on the big side. So it seems common belief that a 16cm works best on the first gen 6bt. So could you just use a housing that is 33% smaller for the 4bt?

18cm 33% smaller = 11. 88cm

16cm - = 10. 56cm

14cm - = 9. 24cm

12cm - = 7. 92cm

So a 10. 56cm housing on a 4bt would be the same as a 16 on a 6bt ect... but there is no 10. 5 housing, the closest is a 12 or a 9 I think? Maybe you could port an Hy35/9cm housing or just get a 12 and live with it(gotta be better than an 18). Maybe a 14cm works great on 6bt's also, in which case a 9cm would be very close? Any other idea's.

Also, this engine is in a 1978 Ford bread truck but appears to have a round bell housing (to a 4spd) and not the chevy version that I usually hear about. The starter is still on the pass. side but would a nv4500 or 47rh bolt up to this?

 

[rbalcom]

Sounds like an industrial pattern... . In order to determine the SAE number post a picture or count the # of bolts ... . mine came with a chev pattern and t400.....

 

[EColeman]

The bellhousing/engine plate definetly is not the same as my dad's 99' DC. It is a perfect circle, looks alot bigger in dia, and about 5 inches deep (have'nt mesured yet) and is probably hooked to a T19 or NP435? I'll try and get some pics soon, it's still in the truck. Will most likely be looking for a dodge/cummins engine plate if anyone know's where one can be found? I plan on putting this in a 90-95 era toyota pick-up or 4runner. Going to be tight... .

 

[rbalcom]

I have a chevy engine plate if you are going in that direction... .

 

[HoleshotHolset]

There's a dude from PA that put a 4BT in a Toyota truck... I saw it on display at Thunder in Muncie. It really didn't look like that bad of a shoehorn fit...



Matt

 

[EColeman]

Thanks for the feedback guys. I'm pretty sure I'll be going with a nv4500 or 47rh so I'm looking for a dodge plate. If you know anyone who is interested in what I believe is a cummins to ford/4spd man. trans set-up I'd be willing to sell it/trade(located northeast AZ). The trans has a parking brake drum on the rear, hydraulic clutch, and seems in ok shape.