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Need help with 1988 GMC 350
jpnc posted a topic in 1988-1999 Chevrolet & GMC C/K GMT400 PlatformHello everyone, I'm new to the site. I have a 1988 GMC Sierra 1500 long bed pickup. It has a 305 Tbi with a turbo 400 and 3.42 rear end I have a 1993 350 Tbi engine and I want to install it with a 700R4 transmission. I will have to get a different PROM (chip) for the 350 and 700r4......."ASDU" i think I have 3 speed cluster in it now. Will I have to change it?...The 700R4 is a 4 speed What all do I have to change for the engine and transmission to fit? ( drive shaft, and etc) I have a 1991 GMC Sierra 1500 5.0L engine, 700r4 transmission for a donor truck Will I have to change the wiring harness under the hood? or all of it?