What gears to use?

[shortbed70]

My 65 has a th 350 trans with manuel valve body, jasper 355 stock(for now) and 15x10 25.5 tall tire. What gears would work best for me . I live right off the highway 65mph and mostly do weekend driving to shows and parades but with the gear now at 3800 rpms I'm still getting passed quickly. I'm considering putting 3.08 because of the short tire 295-50-15. I don't care about gas I just want something that will still smoke the tires at will. I cant afford an overdrive trans new and I've heard bad things about stock 700s what to do???

[mikep]

3.08's will work with short tires like that. Its kind of on the low end of what will give reasonable performance but one guys reasonable performance is another guys dog . A stock 350 would do OK with that gearing but if you went to more cam it wouldnt be much fun to drive.

The 700R4 will work well behind resonably stock motors that aren't driven hard. Hard being a relative term. If youve ever managed to blow up a tranny or break a converter and then did it again the R4 probably wouldnt be for you. If you are just a cruiser then it might be a good idea.

[shortbed70]

Well I've never blown up a tranny but I think I drive pretty hard just not all the time. If some little ricer or muscle car pull up I want to run them and theres no better felling than seeing there face when you hit second and lay 10 foot strip but I need something more streetable. I can get a 90's 700r for 300 bucks but Will I still have to shorten the shaft? Would a 2004r bolt in with no mods and hold up?

[Nova_Cobra64]

I have a 355 in my 69 with a a decent cam and have 3.08 gears. Great for speed and gas mileage, but terrible on the bottom. Depending on the ground some times I can't even break them free. When I can break the tires free and get the engine up to about 3000rpm, they will smoke forever.

I think I would enjoy the truck more with 3.55 or 3.73 posi.

[540 Stroker]

3.55 or 3.73. Anything less would compromise overall performance too much. As for the 700-R4 issues- don't worry. The aftermarket has all the upgrade parts to make the 700-R4 plenty strong and reliable. The nice setup would be your 4.11s combined with the deep first gear of the 700R4-you'd have some wicked launches.

[540 Stroker]

shortbed 70-Check out the May issue of Chevy High Performance. They have a article about the 200-4R and how to make it survive behind a high performance engine. I believe they also said the 200-4R is the same length as a TH350 so it's pretty much a direct bolt in.

Your best bet is to find a 200-4R from a wrecked 1987 Grand National/T-Type Regal or 1989 Turbo Trans Am if you want to use a trans that you don't have to "modify." Those cars put out 245 + hp and well over 300 lb-ft of torque, so that particular breed of 200-4R can handle decent power/torque without mods.

The 700-R4 is a little bit longer than the TH350, so you'd have to have your driveshaft shortened. No big deal.

[dion]

I went with the 3.55 Good all around gear.