The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - Need to know a 383 w/TH350 in a 1964 GMC truck longbed?

**Captainfab** · 05-05-2016, 11:50 PM

Installing an OD trans behind the I6 or changing the differential gears as well as taller rear tires will help reduce your highway rpm's. What rpm's is your engine turning at 50mph?

05-05-2016, 11:50 PM	#8
Captainfab 60-66 Nut Join Date: Mar 2007 Location: Coeur d'Alene, Idaho Posts: 23,254	Re: Need to know a 383 w/TH350 in a 1964 GMC truck longbed? Installing an OD trans behind the I6 or changing the differential gears as well as taller rear tires will help reduce your highway rpm's. What rpm's is your engine turning at 50mph? __________________ Power Steering Box Adapter Plates For Sale HERE Power Brake Booster Adapter Brackets For Sale '63-'66 HERE and '67-'72 HERE and '60-'62 HERE and "60-'62 with clutch HERE Rear Disc Brake Brackets For Sale. Impala SS calipers HERE Camaro Calipers HERE D52 Calipers HERE 6 Lug HERE Hydroboost Mounting Plates HERE