The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - Definitive answer for I6 to SBC 350 swap.

*randy500* · 05-09-2017, 11:23 AM

The engine will bolt up with no modifications at all to the 250 6 cyl frame stands but not the 292 frame stands. If I remember right the rubber engine mounts from the 6cyl are the same as V8, so remove and install those too.

The clutch Z bar will line up with a hole in the block where you will have to source and install a pivot ball with a threaded end. The threads are 7/16 or 1/2 inch, the ball is not hard to find and is used on 4wd trucks of the same era.
You will have to adjust the linkage from the Z bar to the throw out arm.

A 2wd fan shroud will work with a little longer fan spacer, please use a stock fan as those aftermarket ones suck and are dangerous. A 4wd fan shroud may work, haven't tried that. You will have to source longer radiator hoses, the lower one from a 4wd might work, factory 4wd upper had a metal tube and 2 short hoses, I think a replacement hose is made which eliminates the metal pipe so that hose might work.

05-09-2017, 11:23 AM	#5
randy500 Account Suspended Join Date: Jul 2016 Location: Tacoma, WA Posts: 6,873	Re: Definitive answer for I6 to SBC 350 swap. The engine will bolt up with no modifications at all to the 250 6 cyl frame stands but not the 292 frame stands. If I remember right the rubber engine mounts from the 6cyl are the same as V8, so remove and install those too. The clutch Z bar will line up with a hole in the block where you will have to source and install a pivot ball with a threaded end. The threads are 7/16 or 1/2 inch, the ball is not hard to find and is used on 4wd trucks of the same era. You will have to adjust the linkage from the Z bar to the throw out arm. A 2wd fan shroud will work with a little longer fan spacer, please use a stock fan as those aftermarket ones suck and are dangerous. A 4wd fan shroud may work, haven't tried that. You will have to source longer radiator hoses, the lower one from a 4wd might work, factory 4wd upper had a metal tube and 2 short hoses, I think a replacement hose is made which eliminates the metal pipe so that hose might work.