BB swap - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Mudhuny · 05-21-2002, 08:26 PM

I am new to this group, so bear with me. I'm looking to swap a BB into my 72 3/4 ton 4x4, w/ 350 & 4-speed, and am wondering what kind of problems, etc, am I looking at. I've heard that the bell housing will mount up correctly, but am wondering about motor mounts and cooling capacity. Any help will be greatly appriciated.

**Desert Rat** · 05-21-2002, 10:54 PM

Ok i have done this swap a few times not on a 4x4 but they never came with a BB so you will use your existing mounts.but you will need all the pulleys,brackets,fan shroud,cooling depends on your radiator if your truck is a AC truck id use existing radiator.My truck was original SBC with AC i put in 402 live in AZ and temp gauge barely moves.

Scrub · 05-21-2002, 11:00 PM

Dang,
I wish we had a search function. This topic was covered pretty well about a month ago.

I've never done it, but here is what I remember from the thread.

The distributor will bang on the firewall unless you:
Put a body lift or..
Bang a dent in the firewall or..
Move the engine forward, thus needing two new driveshafts, 4x4 Linkage work, Fan shroud, move the transfer case cross member, clutch linkage etc

The easiest was to bang a dent in the firewall for the distributor.

Mudhuny · 05-21-2002, 11:04 PM

Thanks for the help. I figured that it was probably covered before I came to the group. The main thing I was wondering about was if I could use the existing motor mounts, or if I needed to weld/fabricate some new ones on there.

**Classic Heartbeat** · 05-22-2002, 01:36 AM

You can use your existing motor mounts. I have done this swap in my 4X4 Blazer. I have a 402 BB in it. You will have to dent the firewall for the short only valve covers because the tall ones will not fit unless you cut holes in your firwall. Or you will have to do a 2" body lift to get the clearence you need. WES www.ClassicHeartbeat.com

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05-21-2002, 08:26 PM	#1
Mudhuny Registered User Join Date: May 2002 Location: Tieton, Wa. USA Posts: 9	BB swap I am new to this group, so bear with me. I'm looking to swap a BB into my 72 3/4 ton 4x4, w/ 350 & 4-speed, and am wondering what kind of problems, etc, am I looking at. I've heard that the bell housing will mount up correctly, but am wondering about motor mounts and cooling capacity. Any help will be greatly appriciated.

05-21-2002, 11:00 PM	#3
Scrub Collector of rusty Items Join Date: Dec 2001 Location: Sisters,Oregon USA Posts: 731	Dang, I wish we had a search function. This topic was covered pretty well about a month ago. I've never done it, but here is what I remember from the thread. The distributor will bang on the firewall unless you: Put a body lift or.. Bang a dent in the firewall or.. Move the engine forward, thus needing two new driveshafts, 4x4 Linkage work, Fan shroud, move the transfer case cross member, clutch linkage etc The easiest was to bang a dent in the firewall for the distributor. __________________ Scrub Sisters, Oregon - Home of the Sisters Rodeo. 70 GMC 1,000,000 + miles 72 K-20 project, 456 Dana60 front, Corp14 rear w/locker, 265R19.5 tires 20-ply. Warn 12k winches both ends, Cross-over steering with raised tie-rod, Powerbox steering, 4500 watt 120-AC power, Air, Hydraulic aux power, 4 inch lift, 5000 lb air-bags both ends.

05-22-2002, 01:36 AM	#5
Classic Heartbeat Project Junkie! Fishing Poor!! Join Date: Dec 1999 Location: Olympia,Wa. 98512 Posts: 10,770	You can use your existing motor mounts. I have done this swap in my 4X4 Blazer. I have a 402 BB in it. You will have to dent the firewall for the short only valve covers because the tall ones will not fit unless you cut holes in your firwall. Or you will have to do a 2" body lift to get the clearence you need. WES www.ClassicHeartbeat.com ------------------ Click (Here) to visit our on-line catolog. E-mail me WEHEPP@attbi.com 72 BB Chevy Blazer 72 BB Chevy Short Fleet 72 SB 3/4 Ton 4X4 72 SB 1/2 Ton SWB 4X4 70 BB Chevy Short Step 70 SB Chevy Short Fleet 69 SB Chevy Short Step 68 SB Chevy Short Step 68 BB GMC Long Fleet 67 GMC 1/2 ton Panel "Founder" Classic Heartbeat Pickup Club Olympia, Washington's "Home For Wayword Chevys" www.ClassicHeartbeat.com __________________ On-line catolog Classic Heartbeat Pickup Parts WEHEPP@comcast.net Call us Toll Free (888) 338-2502 Like Us on Facebook No appointment necessary. 72 BB Chevy Custom Deluxe / Custom Camper 67 I-6 (Soon to be 5.7 LS1) Panel 68 BB Chevy Short Bed 72 6.0 LQ9 Short Bed Chevy 4X4 Olympia's fastest growing truck parts supplier. Olympia's home for Wayward Chevys

05-21-2002, 10:54 PM	#2
Desert Rat Senior Member Join Date: Dec 1999 Location: Darrington, Washington Posts: 3,963	Ok i have done this swap a few times not on a 4x4 but they never came with a BB so you will use your existing mounts.but you will need all the pulleys,brackets,fan shroud,cooling depends on your radiator if your truck is a AC truck id use existing radiator.My truck was original SBC with AC i put in 402 live in AZ and temp gauge barely moves.

05-21-2002, 11:04 PM	#4
Mudhuny Registered User Join Date: May 2002 Location: Tieton, Wa. USA Posts: 9	Thanks for the help. I figured that it was probably covered before I came to the group. The main thing I was wondering about was if I could use the existing motor mounts, or if I needed to weld/fabricate some new ones on there.



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