here is my questions for you all,,I have a 64 chevy c10 with a 250 and 3 speed.What I am wonderin is what would be a good choice for the rearend in it..The stock rear seems to be pretty low geared at highway speeds and I am looking for something a little more road friendly,,and I would still like to keep the 6 lug wheels..Is there a a factory rear to look for or would it be better to put new gears in the rearend I have?
You could get any rearend out of a coil spring Chevy truck up through 70 model year. Lots of them had 3.08 gears. I actually had a 64 that had original 3.08 gears. Look for the V8, auto trans trucks usually.
I've never seen the 3.07 gears in a 60s truck...but I did find a mid 70s van with a 12 bolt truck rear in it, got the whole rearend pretty cheap and stuck the gears and diff carrier in it (different offset ring gears when you to from 3.73 or over to 3.40 or under) A truck with a six might want 3.40 gears... very common ratio in 70s pickups and suburbans
I have two 67-70 truck rears now with 3.08 gears. Shame he's not closer. I part out these old trucks for extra folding money.
Need more info. What are your current gears that you are unhappy with? What size tires you running? The factory 6's were typically geared lower for more torque, but you need to tell us what gears you have, what size (dia. is preferred so we don't have to go look up conversions for you) and what RPM you desire at highway speeds. Once you get all that, then you can search for an R&P calculator. Randys Ring and Pinion has a good one on their site. It's just a simple matter of putting in the numbers and pressing "click" after that. As for finding a new rear or changing the R&P, it's usually cheaper to find a junk yard rear, BUT if the gears are toast then you're back to square one. Swapping out the R&P is not hard if you have a few special tools and know what you're doing, but it's not really for the first timer, weekend kind of deal unless you pretty comfortable with doing mechanical things. There are lot's of tutorials about it on the web as well. Look at 4x4 sites because they are changing R&Ps all the time.
that would be great if i had the money,,but right now I dont ,,my tire size is 235/75-15,,I dont know what gearing I have now,,all I know is if I'm goin 60 and let off the gas a little it nose dives,,so I figure it s pretty low gear,,where would I look for gear ratio,,there is no tag in the glovebox,,,
block the front wheels, jack up a rear wheel, turn it two turns exactly and count the number of turns the driveshaft turns. That's the ratio. for example if it turns 3-3/4 turns then it's a 3.73 ratio. if you turn the wheel 20 turns and divide the driveshaft number by 10 you'll get a more accurate reading.
Squirrel is right about figureing it out on you own. But you may get lucky and find a little tag hanging off one of the bolts on the rear cover. My '65 was a 6 cyl 3 speed truck from the factory and had a 3.08 in it. Of course it could have been changed but I kind of doubt it. I should probably bite my toungue here but it could just be that your nose dive is caused by compression. Oh probably not it is an inliner.
Yeah a 250 with a manual trans. You prolly got 373 gears. That is what my big 10 has, and your right it is not highway friendly. but in answer to your question. I would keep your original housing and just replace the gears, if available. That way you know they are good to go. 3.0s would give you a lot better highway use, and not destroy your around town cruising. anything higher or lower and it wouldn't be cost effective. Then all you got to do is find an old saginaw 4 speed and let the fun begin...John
I saw the suggestion for the T-5 trans and would agree. We just did one in Kelly's 62 GMC just before leaving for the Round Up a few months ago. Trans was from a 2.8L V6 S-10 truck on half price day at the U-Pull-it $75.00 Disc from an Astro van $50.00 http://www.summitracing.com/parts/ZZZ-RCF4212/ We found a drive shaft here that fit perfectly, just needed new U-joints $25.00 each. I can get a new drive shaft made for under $200.00 Three quarts of syncromesh oil, we used the Royal Purple equivalent $45.00 The rest was a bit of labor. I think the whole process took under 6 hours because we have a lift in the shop. But not beyond a backyard install. Seriously for under $400 bucks we got much better shifting and a great freeway gear!
A 250 and a 3 speed don't have any extra power for any adverse conditions hills, head winds etc. We ran them trucks all the time 70-75 stock gears no sweat, 3.70-3.90s. Turning 3000-3500. Flat land no load maybe 3.30 odd for the highest. I was in on Kelly's GMC ****** swap and drove the truck before and after,The 5 speed made that truck. Still had gears for pull and freeway happy too.and the GMC was a V-6 which don't like to rev like a 250 inline.
Like I said before,,would love to do a t-5 swap and have looked into it before,,but for right now,,I just cant afford it,,just tryin to find a junkyard rear that I could swap in and get the revs down on the road,,but thanks for the advise
I think a ****** swap is easier than a rearend, personally. Once you figure in bleeding the brakes and rebuilding the drums, etc. The improved driveability from a t5 is absolutely worth it. No doubt about it. It can be done with junkyard parts under $200. And I have done both, in the gravel, in the summer. 12" of snow on the ground. Did I mention it was uphill?
Friend I don't want to **** in your cornflakes but changeing the rear will cost you about the same as a ****** swap.
That's fine, it's just my opinion and seems to be the opinion of others, that a different gear ratio rear axle is going to be difficult to find in a junkyard. And if you do, it may be a cheaper option to swap the trans instead... Typical cost of a used rear axle around here is getting north of $250.00. Good luck in your search The 73 and up trucks with diesels have some low geared rear ends. The 78 I had a while back had 3.2? something gears. These are a bit different, the bolt pattern is 5 on 5 and you will be required to remove the axle pads and install new ones to match your trailing arms and possibly a new mount for the panhard. If this is a parallel leaf truck things are a bit easier, still have to deal with the wheels.
finding tires that are 20% taller than the normal sized tires that are probably on it, will be kind of difficult...unless he goes for the 4x4 look
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