3:73 with a power glide/ to turbo 350?

[Tripmiester]

Guys,

I have a stock 1965 C-10 with a 283 hooked to a powerglide with 3:73’s
I bought it with some 2006 17” 31” tires, I have been restoring it and went back to the stock dog dish rims and 28” tires. When it had the 31” tires on, the rpm’s werebup there on the highway. I know when I get her back on the road with the 28” it will be even higher. Will the Turbo 350 bolt up and be the same length, and have any benefits as far as lowering Rpm on the highway?
Any other modifications needed if I do so? Looking for advice Pro’s and Con’s?

Steve

[Grounded63]

No, the final drive will still be 1 to 1.

You'll need an OD trans. To help with lower rpm's on the highway.

[jayoldschool]

TH200 4R will be a bolt in for the PG, same length. There are comparison websites out there.

[Tripmiester]

Oh, well that is that!! I used a rpm, gear, tire size calculator and looks like 75mph I’ll be running 3,350 rpm’s.
I’ve been told power glides are pretty tough not to worry, Agree?

[jayoldschool]

No one ever worried about turning 3k on the highway until the OD transmissions came out. I drive my PG-equipped 327 65 Impala on the highway at 75. The truck with the 230/3 speed manual... I keep it 60-65. Mostly because it's much noisier, lol

I do like my T56-equipped (double OD!) 96 Impala... 75mph is 2000rpm in 6th... with 4.10s ;-)

[Brochacho]

I have the same problem on the highway with same motor/transmission as you. I am planning a swap with a 700 R4.

[SkinnyG]

I drove my squarebody for nine years with 3.73's, TH350, and 26.6" tires (295/50R15).

It might be a bit buzzy compared to modern cars, but it's fine; a 283 can take it. A good excuse to run a rowdy camshaft that starts making power around 2800rpm or higher (big grins).

[Brim]

Originally Posted by SkinnyG

I drove my squarebody for nine years with 3.73's, TH350, and 26.6" tires (295/50R15).

It might be a bit buzzy compared to modern cars, but it's fine; a 283 can take it. A good excuse to run a rowdy camshaft that starts making power around 2800rpm or higher (big grins).

Agreed mine Lwb 64 has 283, TH350, 3.73’s and a 27 1/2 rear tire. Cam pulls hard to about 3,800 or a tad more. Only thing with an automatic can’t get no tire chirp. 😎

[theastronaut]

3300 rpm on the interstate is fine, it won't hurt anything. Converting to an electric fan will cut down on noise noticeably, the original direct drive fans are fairly noisy at higher rpm.

I've done a lot of highway/insterstate driving at 75 with no issues, even when towing a car trailer. Mine has a 250, 3 speed on the column, 3.73 gears, and 28-29" tall tires.