Inliners International Forums General Discussion Drive Train Rear Axle Choice for a 46 GMC 1/2 ton

Help would be greatly appricated, my 46 GMC 1/2 ton truck currently has a GM axle L 1-5 #3707306, I have no clue what it came out of. Question, is this axle worth keeping or does anyone have a suggestion as to a good axle to replace it with that wont cost me both my arms and both my legs. I plan to use a 292 chevy engine with a 700R4 tranny, my intent for the truck is more in line with a daily driver/cruiser rather then anything that I would consider raceing with.

Dear Rick;

Check with Patrick's in Casa Grande, Az. for advice on this. There number is: (520) 836-1117.

Tom's Truck Parts should have the item(s) you need as well.

Good luck.

Do you want 5 or 6 lugs?

prefer a 5 lug over a 6 lug in this case

Most older car rearends will fit, it comes down to how much rim backset you want to run.
55-64 car, 69-74 Nova, 4WD S10's are some of the more common choices, but there are others as well. Just take a tape measure with you to the salvage yard...

Dear Rick;

Passenger car 'rearends' are not designed for use in trucks. They can be made to work but won't carry any kind of a load that the truck was built for.

Go with the 4WD or S-10 as he sugests.

Good luck.

He building a cruiser hotrod, not a dump truck.

FWIW, The S10 axle is actually the weakest of all at only 7.5" ring diameter, where the other "car" ones are 8.2" or 8.5". Some 4.3 S10's had a 8.5"? in them, but it's the same as the "car" anyway. The main reason people use the 4WD S10 rears is that they are easier to get than the older ones, and they are the right width for most applications. Most of the people on this site are running well under 300hp, so durability isn't really an issue. If it is, then get a custom made 9" Ford rearend or 8 3/4" Mopar or a Dana 60.

Basically, all GM c-clip rearends are the same, its just the size of the ring gear and axles that changes.

Dear Bryan;

I didn't read anything there that stated he wanted less load capacity/durability.

This is why I refered him to Patrick's who builds trucks & Tom's who sells truck parts of that era. Both of which are professionals in the industry.

S-10 Chevrolet & 4X4 trucks have a GVWR close to that of his GMC, keeping his vehicle the same basic opertional design etc.

This should be a "no brainer".

Believe it or not, I have personnally worked on all of the above, and have used all of the above.

If a 7.5" S10 rearend is good enough for the task as you state, then wouldn't it stand to reason that a car rearend of 8.2" or 8.5" would work also? talk about a no brainer...

If the goal is to use a 5 on 4 3/4" pattern, then there isn't any other choices without custom axles and drums.

i have a 78 camaro rear in 46. and again gearhead is right that style rear has bigger bearings and gears thenn the later s10 rears.

Gentlemen;

I think were getting "off trac" here, as the purpose of 're-designing' anything is to upgrade it, not the reverse.

All trucks have a GVWR (gross vehicle weight rating) by the MFG where passenger cars do not. This is because cars carry their weight evenly over both axles/all 4 wheels.

Trucks 'on the other hand', carry their weight to the rear of the wheelbase (center) over the rear axle(s) and this is why they are built differently (extra heavy)etc.

The Spicer type 'rear ends' are similar as stated, but the truck ones are desinged for trucks and have this extra load capacity.

If we all could say his truck would never carry a load (ever), then it wouldn't matter a bit what he put in there.

Happy trails.

Once again, you have completely missed the point I was making. If anyone else feels the same, feel free to email me and I will explain why...

i can say one word elcamino. they used the same rears as the cars they were based on. and they were rated the same as a 46 i/2 ton truck.

thanks to all for your help and advice, do appriciate the advice from very experienced and pationate folks, to all I tip my hat to you