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Mikefromcny 07-17-2012 18:57:10 74.78.198.207 Report to Moderator	Just curious if anyone has a changed the rear axle gears (2spd) in an old c50-c60-c70? I have an 84 C70, 366 gas, 5 speed, 2 speed rear. Unsure of rear axle ratios, but it seems like I can afford to go higher, I can start in 2nd high empty. It has a 20ft rollback bed on it. Its just used occasionally to move tractors, but it when is the speed limit is 65 on the highway, the 366 is turning 3300rpm at 55. 22.5 tires on the truck. Not sure where I can buy a different ring and pinion or how difficult it is to change, seems like there would be some good used rear ends kicking around from people scrapping the rest of the truck. Any Ideas are welcome. Thanks guys. [Reply]   [No Email]
d beatty 07-20-2012 20:08:51 24.12.128.253 Report to Moderator	Re: Regearing a '84 chevy c70? in reply to Mikefromcny, 07-17-2012 18:57:10   The freight line that I worked for had three Chevy box trucks set up with a 366 with a 5-2 behind it and would do 70 mph with a pay load of about 12,500 lbs. We also had about ten semi tractors set up the same way.They were running ten hundred twenty's for tires back in the late 70's through the 80's. [Reply]  [No Email]
big a 07-18-2012 21:09:03 98.19.46.230 Report to Moderator	Re: Regearing a '84 chevy c70? in reply to Mikefromcny, 07-17-2012 18:57:10   Just a thought, but would the 3rd member out of a GM school bus possibly contain higher gears? Might be cheaper and easier than swapping ring and pinion when all is said and done. [Reply]  [No Email]
hd6gtom 07-18-2012 16:07:11 75.170.237.148 Report to Moderator	Re: Regearing a '84 chevy c70? in reply to Mikefromcny, 07-17-2012 18:57:10   Mike If the 4 bbl carb is set right you will have plenty of power with the 366 to go to taller gears. I owned several of them, bought new in the 70's. They would all run 75 mph with loads on them. One had a low 1 gear, clark tranny but would top out at 80+ mph with no trouble. Keep in mind, hauling tractors or farm machinery is a hard pull no matter what setup you have. [Reply]  [No Email]
onefarmer 07-18-2012 12:01:25 66.87.2.92 Report to Moderator	Re: Regearing a '84 chevy c70? in reply to Mikefromcny, 07-17-2012 18:57:10   Maybe a Ranger overdrive would work for you. It would install ahead of the trans, so no need to change the speedo gears and no need to open the rearend. Advance Adapters [Reply]  [No Email]
The tractor vet 07-18-2012 08:07:20 76.212.234.198 Report to Moderator	Re: Regearing a '84 chevy c70? in reply to Mikefromcny, 07-17-2012 18:57:10   Look for a truck salvage yard and start looking around . Ya ya can swap out the pig for a higher gear ratio but the comes the problem of the speedometer gear changes not only in the transmission but the two speed thing as what they call that escapes me at this moment. The next down side is that when ya make the gear swap with a gasser is the loss of pulling power as them old gas truck engines were no power house . Might be a lot less of a hassle to go find a older diesel box truck that has more road friendly gears and remove the box shorten up the frame to your needed length and move your bed over on to the new diesel.Over here finding a diesel box truck is not hard and making it into what you want requires a little work to shorten them up by unbolting the rear axle and moving it ahead to what ever wheel base you need and redrill some holes and shorten up the drive shaft. [Reply]  [No Email]
timcasbolt 07-18-2012 05:36:15 72.23.207.250 Report to Moderator	Re: Regearing a '84 chevy c70? in reply to Mikefromcny, 07-17-2012 18:57:10   Never done one in a big truck, but have done lots in cars and pickups. The parts are very heavy, but the work isn't complicated. You can get step by step instructions on the internet. I doubt you'd consider it time well spent though. [Reply]  [No Email]
danofarming 07-17-2012 19:00:18 69.8.164.11 Report to Moderator	Re: Regearing a '84 chevy c70? in reply to Mikefromcny, 07-17-2012 18:57:10   You could put 11 R 24.5 rubber on it that would boost your speed bout 5 mph. [Reply]  [No Email]