UGH C20 rear end dilemma
 

OK some of you may know I bought a 65 C20 327/Th400 recently. Well I finally got the chance to drive it the other day. The engine runs excellent. The truck handles great. I'm impressed how well the power drum brakes stop. I plan on this truck to be my daily driver weather permitting April-November.

Now the bad part. I want to drive faster then 45 mph without the rpm's roaring. I believe but have not confirmed yet that my Eaton HO52 has 4.57 gears. Even it had 4.11 I don't think it would help much. I plan on swapping the TH400 for a 700r4. But I don't think that will get me to where I want to be. I really want to be able to cruise comfortably at 65 mph.

After doing much reading I can't find the perfect match 8 lug axle with the same Wms as mine. (approximately 65"). I would like to keep the truck 8 lug. the only thing I found close would be 14 bolt from a cab and chassis truck. (63.5") then I would have to redo the axle to accept coil springs.

I did find someone local to me that has a 6 lug 12 bolt out of a mid 60's C10 with 3.73 gears. He also has a 5 lug 10 bolt out of he thinks a 1972 C10 with 3.42 gears. both are reasonably priced.

I'm just trying to decide do I want to take my C20 and make it a half ton. I do plan on going with disc up front sooner or later so I could change over the front to match the rear if I do swap to a different bolt pattern.

I know the decision ultimately lays in my hands. I'm just
looking for some advice.

Here's a link to my truck in question. http://67-72chevytrucks.com/vboard/s...d.php?t=615628



Sorry for the long post, Matt

Re: UGH C20 rear end dilemma
 

im in the same boat, have 64 with eaton rear with 4.56 gears, i picked up half ton rear and crossmember to do switch . i plan on using truck as daily driver as well so i think for me i will do rear first seems the easiet to me

Re: UGH C20 rear end dilemma
 

So if I swap to a half ton rear end I need to change the cross member too?

Re: UGH C20 rear end dilemma
 

yea if you want same lug pattern in the front

Re: UGH C20 rear end dilemma
 

OH okay I misunderstood you. I was thinking the rear crossmember by the axle.

Re: UGH C20 rear end dilemma
 

Use a DANA 60 out of a same generation GMC ¾ton. They can be geared as tall as 3.54.
Not a bolt in but the width should be right and it's 8 lug. I can measure whatever you need on my 62 if it helps.

Re: UGH C20 rear end dilemma
 

Yes a Dana 60 from a '67-'72 would be a direct bolt in, but those aren't exactly easy to come by. The '68-'72 Dana 60's behind a big block and an auto trans had the 3.54 gears.

Depending on what tires and wheels you are running the '73-'87 14 bolts can work. I do make trailing arm mounts specifically for the 14 bolts should you decide to go that route.

Re: UGH C20 rear end dilemma
 

Thanks for the suggestion and the offer to measure the rear end. Parts for these trucks around here are like a needle in a haystack.


Thanks for the information. I did read that I could use a 73-87 14 bolt and I also did read you make the parts to do this. Right now I'm running a set of factory steel wheels off a 90'ish Chevy truck. I only have about an 1.5" between the tire and inner wheel well lip on each side.

http://i17.photobucket.com/albums/b7...303_122840.jpg