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73-87 Chevy _ GMC Trucks => Performance => Topic started by: Grover 1 on July 20, 2009, 07:30:31 am

Title: Engiine swap
Post by: Grover 1 on July 20, 2009, 07:30:31 am: I have a 1978 1/2 ton short wide pick up. It currently has a Goodwrench 350 and a turbo 350 transmission. I have a chance to pick up a period correct 454 and a 400 trans than are currently in a 78 pickup. The 454 was rebuilt about 60,000 miles ago and the 400 about 20,000 miles ago. I can get the whole truck for $1200.00. Is there a lot of other expense in swapping to a big block? I figured motor mounts, exhaust, perhaps a change in drive shaft length and maybe front springs would be about it. My 78 is a Big 10 so it already has the large radiator in it. Am I missing anything else of real importance? - thanks, Grover
Title: Re: Engiine swap
Post by: zieg85 on July 20, 2009, 05:58:22 pm: If you have the whole truck it should be a piece of cake. Don't expect to get better gas mileage though... ;D
Title: Re: Engiine swap
Post by: Mr. Lee K30 on August 07, 2009, 12:02:21 am: Motor mounts yes, there is a difference between the small-block and big-block mounts. Not too expensive though :)
(http://i633.photobucket.com/albums/uu59/Darknight455/Chevy%20Truck%20Stuff/SBvsBBMotorMounts2.jpg)

As long as the 454 donar truck is a true factory 454 rig everything should swap alright. Working on the same swap in my '77 Crew Cab minus the tranny part
Title: Re: Engiine swap
Post by: dumbucket1 on August 07, 2009, 07:38:57 pm: Motor mounts do interchange between the two motors I have done it a couple times
Title: Re: Engiine swap
Post by: joesgarage71 on August 07, 2009, 08:34:35 pm: Quote from: dumbucket1 on August 07, 2009, 07:38:57 pm
Motor mounts do interchange between the two motors I have done it a couple times

I never had a problem

You need the gas pedal, kick down wiring and switch, fuel lines. get the whole truck! sell what you don't use
Title: Re: Engiine swap
Post by: Texcuda on December 26, 2009, 06:47:31 pm: Quote from: joesgarage71 on August 07, 2009, 08:34:35 pm
Quote from: dumbucket1 on August 07, 2009, 07:38:57 pm
Motor mounts do interchange between the two motors I have done it a couple times

I never had a problem

You need the gas pedal, kick down wiring and switch, fuel lines. get the whole truck! sell what you don't use

The gas pedal? Is there a difference in cable length? I'm swapping my 82 to a BBC. Thx
Title: Re: Engiine swap
Post by: 78 Chevyrado on December 26, 2009, 08:34:56 pm: You need the gas pedal stuff to use the TH400. a TH350 uses a kickdown cable, but the TH400 does not. there's a switch mounted to the gas pedal bracket that controls downshifts alongside the vaccum modulator.
Title: Re: Engiine swap
Post by: Texcuda on December 27, 2009, 02:18:38 pm: ooh nevermind, the kick down switch is not required for t400 is your using a full manual valvebody, I thought you talking about a different pedal assembly for a sbc to bbc swap.