Big Block Swap Problems? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

duke68ss · 12-13-2003, 06:33 PM

I am thinking of yanking my SBC out of my 68 GMC for a 468 BBC..Anything I should know about b4 I start?.. Tips, Past experiances, Extra Parts.. Thanks!!

**BIG ORANGE** · 12-13-2003, 07:21 PM

Change the engine towers from the sbc to the bbc 1st and put a 4flu radiator in and you might want to upgrade your starter to a hightorqe style then put in a high CCA battery! Thats about all I can think of right now,Oyeah go with 2 1/2 exhaust!

Tx Firefighter · 12-13-2003, 07:32 PM

The alternator and power steering brackets and all the pulleys are going to cost a fortune.

Engine frame stands are expensive too.

I know all of this because I'm in the middle of a big block swap right now.

miket · 12-13-2003, 11:05 PM

Check out my site....just went through it with my 502 swap.

Longhorn Man · 12-14-2003, 12:10 PM

The motor mounts will cost quite a bit regardless which one you use.
The 67 - 71 have real cheap towers, but the mounts will make you slit your wrists.
Then the later 72 style you'll crap your self when you see the price on the towers, but the mounts are cheap.

I think some one on here has said you can use the later 73& up big block mounts and towers with little to no fab work. Probably a matter of a few holes to poke in the frame.
Pullies...get them all from one engine. This way you are guranteed they will work. Take notice of the pump length when snagging the pullies. If you are at a junk yard getting them, DON'T tell them they are off a big block...just say off an old chevy in the back of the yard. (the price will tripple if you are 100% honest)
Aftermarket vendors have some very nice pully/bracket set ups too, but again...quite costly.

ChevyDude · 12-14-2003, 12:50 PM

Good luck on the BB conversion. It seems the under lying tone here is: "All is good with the BB conversion....but if you want to play, you've got to pay!"

still w.i.p '68 · 12-14-2003, 02:54 PM

i used regular mtr mounts out of a 80's model truck, 1 hole to drill, and I think the motor sets great, good luck.

12-13-2003, 06:33 PM	#1
duke68ss Registered User Join Date: Dec 2003 Location: Nor Cal Posts: 104	Big Block Swap Problems? I am thinking of yanking my SBC out of my 68 GMC for a 468 BBC..Anything I should know about b4 I start?.. Tips, Past experiances, Extra Parts.. Thanks!!

12-13-2003, 07:21 PM	#2
BIG ORANGE Senior Member Join Date: Oct 2001 Location: Lancaster S.C. Posts: 4,754	Change the engine towers from the sbc to the bbc 1st and put a 4flu radiator in and you might want to upgrade your starter to a hightorqe style then put in a high CCA battery! Thats about all I can think of right now,Oyeah go with 2 1/2 exhaust! __________________ Things happen for a reason!

12-13-2003, 07:32 PM	#3
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	The alternator and power steering brackets and all the pulleys are going to cost a fortune. Engine frame stands are expensive too. I know all of this because I'm in the middle of a big block swap right now. __________________ I'm on the Instagram- @Gearhead_Kevin

12-13-2003, 11:05 PM	#4
miket Registered User Join Date: Jan 2003 Location: Seattle WA Posts: 1,466	Check out my site....just went through it with my 502 swap. __________________ FocuzTech Performance Evergreen Protective Coatings Gatorhyde...the best kept secret in spray in bed lining & protection

12-14-2003, 12:50 PM	#6
ChevyDude Senior Member Join Date: Jun 2003 Location: Westminster, CO Posts: 3,071	Good luck on the BB conversion. It seems the under lying tone here is: "All is good with the BB conversion....but if you want to play, you've got to pay!" __________________ Alex 1971 Lil' Red 350 SBC 700R4

12-14-2003, 12:10 PM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	The motor mounts will cost quite a bit regardless which one you use. The 67 - 71 have real cheap towers, but the mounts will make you slit your wrists. Then the later 72 style you'll crap your self when you see the price on the towers, but the mounts are cheap. I think some one on here has said you can use the later 73& up big block mounts and towers with little to no fab work. Probably a matter of a few holes to poke in the frame. Pullies...get them all from one engine. This way you are guranteed they will work. Take notice of the pump length when snagging the pullies. If you are at a junk yard getting them, DON'T tell them they are off a big block...just say off an old chevy in the back of the yard. (the price will tripple if you are 100% honest) Aftermarket vendors have some very nice pully/bracket set ups too, but again...quite costly.

12-14-2003, 02:54 PM	#7
still w.i.p '68 Dreams are free Join Date: Dec 2002 Location: Hogansville Texas Posts: 546	i used regular mtr mounts out of a 80's model truck, 1 hole to drill, and I think the motor sets great, good luck. __________________ '68 swb fleetside originally w.i.p '68 member since 1-01 w.i.p = ( work in progress )



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