Cummins going in '71, anyone here do it before? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

TP from Cntl PA · 02-18-2005, 03:24 PM

I got a small straight 6 Cummins on the way to replace the 350 in my '71 C-20. It is a 6AT3.4 and about the size of a 292. I would have put a 5.9 in it but I was concerned about the length. Anyone here put a diesel(Besides a 6.2) in one of these trucks? My main concern is on the gearing. I have a load of Saginaw 3spds laying around and kicked around the idea of mounting one behind the original tranny backwards for a poor mans OD. I haven't looked inside one yet to see if it is possible, but I thought that would be sorta different and practical as well. I thought about mounting it like a devorced transfer case and then adding an aftermarket 3spd shifter in the cab to control it. In 3rd it would be like it wasn't there and you had stock driveline, then once out on the highway, put the second tranny up in second and match the main tranny up to the road speed and engine rpm.

Anyone ever try something like this?

02-18-2005, 03:24 PM	#1
TP from Cntl PA Registered User Join Date: Apr 2003 Location: Central PA....In the Berg of Nisbet Posts: 790	Cummins going in '71, anyone here do it before? I got a small straight 6 Cummins on the way to replace the 350 in my '71 C-20. It is a 6AT3.4 and about the size of a 292. I would have put a 5.9 in it but I was concerned about the length. Anyone here put a diesel(Besides a 6.2) in one of these trucks? My main concern is on the gearing. I have a load of Saginaw 3spds laying around and kicked around the idea of mounting one behind the original tranny backwards for a poor mans OD. I haven't looked inside one yet to see if it is possible, but I thought that would be sorta different and practical as well. I thought about mounting it like a devorced transfer case and then adding an aftermarket 3spd shifter in the cab to control it. In 3rd it would be like it wasn't there and you had stock driveline, then once out on the highway, put the second tranny up in second and match the main tranny up to the road speed and engine rpm. Anyone ever try something like this? __________________ '72 K-20 EFI'ed 250 Inline/4spd stake body, Farm Truck '71 C-20 Cummins Diesel Powered, In storage thanks to $5.00 diesel! '69 3500 GMC 305V-6/4spd, Still under reconstruction.......... Inlines Rule! 6 soldiers standing is better than 8 laying down!!!!!!!!



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.