5/8 ton gear ratios?

[woodie70]

i was thinking about changing out my r&p to gain some drivability on the highway.... 70' 5/8 ton, 350, two bbl, 3 speed.... should be 3.73 from all my research... wondering if any of you have done this and have any suggestions.
was thinking 3.08 or 3.38.
i am in the process of building a 90 350 2 bolt now, all stock engine converted to carb.... if i do that and go 350 turbo for tranny would that warrant me choosing a certain ratio.. not building a hot rod, i just drive it every day for now. thanks chad

[special-K]

I`m not familiar with a 5/8t.Never heard of that.What axle do you have?You need to be sure about the exact ratio you have.What form of research did you do?The best research would be drain gear oil,pull cover and either count teeth of find the ratio stamped in the ring gear.You can go with any ratio with what you are doing.If you have a 1/2t/12-bo;t rear you can go with 3.08s.

[woodie70]

Originally Posted by special-K

I`m not familiar with a 5/8t.Never heard of that.What axle do you have?You need to be sure about the exact ratio you have.What form of research did you do?The best research would be drain gear oil,pull cover and either count teeth of find the ratio stamped in the ring gear.You can go with any ratio with what you are doing.If you have a 1/2t/12-bo;t rear you can go with 3.08s.

i will pull cover and look... and as far as research it is various sites and specs i've found on the net.... never heard of 5/8 ton? 3/4 ton suspension in a half ton, 6 lug wheels, stoarge box in the bed? i'll look at mine to be sure on gears, but running a 235/75/15 @ 65mph i'm turning 3k. would like to improve milage and be able to run at least 70- 75. thats why i was thinking 3.08

[67_C-30]

Never heard of the 5/8 either, at least not in these models. I've heard the 73-78 Chevy Big 10's and GMC Heavy Halfs referred to as 5/8 tons, but I don't think they existed in 67-72's. To have 3/4 suspension, it would have to have 8 lugs, unless it just has heavier springs. All regular 67-70 half tons had 6 lugs.

[too much stuff]

A 1/2 ton would have the 6 lug wheels. If you went to a 3:08 gear, that would be your best bet. Also not aware of a 5/8 ton in these years.

[67_C-30]

Maybe that part of the Ultra Rare Cor... - nah, I'm not going to say it!

[woodie70]

Originally Posted by 67_C-30

Never heard of the 5/8 either, at least not in these models. I've heard the 73-78 Chevy Big 10's and GMC Heavy Halfs referred to as 5/8 tons, but I don't think they existed in 67-72's. To have 3/4 suspension, it would have to have 8 lugs, unless it just has heavier springs. All regular 67-70 half tons had 6 lugs.

ok now i'm confused! your telling me all 67 c10's have 6 lug pattern?

[Longhorn Man]

every 60 - 70 1/2 ton GM truck (maybe even older) came stock with 6 lug wheels.
I've also never heard of 5/8 ton, nor seen anything in factory documentation.
A 1/2 ton with heavy springs, is still a half ton. The tool storage box on the side was an option in its self, not related to any packages at all.
Now, if it is a 1/2 ton with a 3speed tranny, then it would in fact have the 3.73 gearing unles opted otherwise.
A 3.08 IMO is a great gear. Gives you the freeway RPMs just a tick higher than an overdrive, and take off isn't nearly as bad as some would make you believe.

[woodie70]

Originally Posted by Longhorn Man

every 60 - 70 1/2 ton GM truck (maybe even older) came stock with 6 lug wheels.
I've also never heard of 5/8 ton, nor seen anything in factory documentation.
A 1/2 ton with heavy springs, is still a half ton. The tool storage box on the side was an option in its self, not related to any packages at all.
Now, if it is a 1/2 ton with a 3speed tranny, then it would in fact have the 3.73 gearing unles opted otherwise.
A 3.08 IMO is a great gear. Gives you the freeway RPMs just a tick higher than an overdrive, and take off isn't nearly as bad as some would make you believe.

thanks on the 3.08 notes, thats what i was looking for. and i apologise for the 5/8 ton, i was mis informed. the truck is older than i am, but i'm getting there. thanks for the info, sorry for my ignorance

[caminokid]

Originally Posted by Longhorn Man

every 60 - 70 1/2 ton GM truck (maybe even older) came stock with 6 lug wheels.
I've also never heard of 5/8 ton, nor seen anything in factory documentation.
A 1/2 ton with heavy springs, is still a half ton. The tool storage box on the side was an option in its self, not related to any packages at all.
Now, if it is a 1/2 ton with a 3speed tranny, then it would in fact have the 3.73 gearing unles opted otherwise.
A 3.08 IMO is a great gear. Gives you the freeway RPMs just a tick higher than an overdrive, and take off isn't nearly as bad as some would make you believe.

My 46 and 50 had 6 lugs with 16 inch wheels.

[Longhorn Man]

Originally Posted by Pl4yboy

He's talking about the heavy half tons. My 69 camper special is like that.

You can call it that... But... GM never did.

Originally Posted by caminokid

My 46 and 50 had 6 lugs with 16 inch wheels.

Sweet.. more info!

[Longhorn Man]

no big deal. Sometimes someone joins with info we've never heard of, and it's real. But more likely, some one has been misinformed. Thats what this place is all about, learning. (on a lesser forrum you woulda been called an idiot, but we won't do that here... not till we get to know you!)

[woodie70]

that's geat! i am an idiot thought, so i'll save u guys the trouble of figurin it out.
no thanks haven't had it long itchin to start on it... fundage is my biggest issue.
i also blew the head gasketon my amc 360 muddin... that's my first priority.
thinkin ahead.

[Pl4yboy]

He's talking about the heavy half tons. My 69 camper special is like that.

[67_C-30]

Originally Posted by woodie70

that's geat! i am an idiot thought, so i'll save u guys the trouble of figurin it out.

You're working a '70 Chevy, so that makes you OK in my book. BTW, we love pics here, so cough 'em up!!

[special-K]

Yeah,I would never raz a guy for being misinformed.FYI,GM just never had such a designation.Even the later Heavy Halfs and Big Tens were still...cough cough...halfs and tens...sniff sniff.