More weird swap questions.....

[qksilver]

Bought a 68 c-30 wrecker 2 months ago for 4 bills. You can imagine what condition it's in for that price.
I have all the sheet metal to get it back to good shape but have questions about mechanical stuff.
The truck orginally came with a 6 so the rear has really deep gears, thought about a 5 speed swap but don't have the money.
Found a complete C-40 truck cheap with a good running 350, 4 speed and a 2 speed rear. Frame and body are wasted but good running gear.
Question is can I install the C-40 rear under my C-30. It has the dually option so the wheels stick out past the body and the wrecker bed has fenders.
So width sin't a problem, I can trim the fenders if I need but are the spring perch widths the same the same on the rears and is it possible to fit 16 on the C-40 rear or can I use the C-40 wheels on my C-30.

I am not able to go to the C-40 and measure stuff for many medical reasons and if I don't buy the truck it is going to scrap.
Any help would be apreciated
Thanks,
Steve

[qksilver]

Ttt

[special-K]

I can`t say for sure,but I believe the rear will swap.Is it 5 or 8-lug?There were the heavy wide 5-lug 1 tons in a light truck body.Then,there were C/40s in the medium-duty body

[72lb4x4]

I think a bit of net research will show that the big truck 2 speed rear ends had lower gears than a C30 wrecker.

[qksilver]

..........what can i say, I was being lazy

[72lb4x4]

Come to think of it, I have a book that says that 2 speed rear ends are 6.10:1 and 8.10:1. I can't say if they all are, but it seems some were anyway.

[jeffspower]

IIRC, the GM 2 speed rears had 6.60/8.83 ratios. Your C30 probably has 5.13's or 4.57's. You can find 4.10's & swap the pumpkin easy enough.

[rwgregory]

I don't know what year your C-40 is but the rear gears are still probably too deep. According to the GM factory overhaul manual, October 1968 edition the gear ratios for the Corporation T150 2-spd. rear axle are 5.83:1 & 7.95:1.

[qksilver]

I was thinking with the larger diameter wheels it would work. It's a 71
My wrecker only has a Holmes 400 on it. If it had a 500 or up I would use the wrecker bed on the C-40 and part the 68 out.
I am thinking about getting the C-40 anyway and down the road make it into a roll back. I can get it really cheap

[special-K]

Get it.They stopped making these trucks only to bring them back more recently.What year is it?I know a guy with a`66 C/40 that is built off the light truck platform(10-30).I`ve seen the HD C/30 in 67-72s that have the wide-5 lug pattern and 19.5 rims.I`ve een 67-72 C/40s that are built on the medium-duty platform.