The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - Want to put in a T56, clutch pedal question.

bloo · 07-14-2019, 12:50 AM

Generally speaking old carbureted engines don't like to cruise that low, even if they are stock and not built up at all.

What gears do you have now? They might be kind of high because it was a Powerglide? All I remember about the gears that were in mine when I got it (decades ago) was that they were ridiculously low. Probably 5.13 or maybe even worse. It could have used all kinds of overdrive. The 283 was screaming for mercy at 55mph.

I would do a little math and see what your RPM in high would really be in sixth, and fifth! Maybe fifth would be just right, and 6th would be for level cruising on 80MPH freeways? Maybe not. Worst case, maybe you change the rear axle gears?

EDIT: I missed in your original post that you have 3.73. Yeah, thats gonna be kind of high.

07-14-2019, 12:50 AM	#8
bloo Registered User Join Date: Jun 2019 Location: Wenatchee, WA Posts: 46	Re: Want to put in a T56, clutch pedal question. Generally speaking old carbureted engines don't like to cruise that low, even if they are stock and not built up at all. What gears do you have now? They might be kind of high because it was a Powerglide? All I remember about the gears that were in mine when I got it (decades ago) was that they were ridiculously low. Probably 5.13 or maybe even worse. It could have used all kinds of overdrive. The 283 was screaming for mercy at 55mph. I would do a little math and see what your RPM in high would really be in sixth, and fifth! Maybe fifth would be just right, and 6th would be for level cruising on 80MPH freeways? Maybe not. Worst case, maybe you change the rear axle gears? EDIT: I missed in your original post that you have 3.73. Yeah, thats gonna be kind of high. Last edited by bloo; 07-14-2019 at 01:12 AM.