4-speed bellhousing crossmember; are BB and SB the same? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Canada20 · 11-05-2002, 11:25 AM

Hey all. Not much to add the to topic line except explain what I'm hoping to do; swap a 454 in place of my 292 and I'd like to keep my 4-speed. Wes has mentioned that I'll need a different trans crossmember for this and I'm curious if I need one from a Big Block truck or are they the same for all V-8's?

Also will a crossmember from a 73+ work?

Thanks

Greg

crazy longhorn · 11-05-2002, 11:38 AM

the 73 up crossmember wont work with your 4 spd truck trans. i know the inline & the sb bell crossmembers are different, & you will need the BB stands & eng mounts......but Im not sure about placement on the BB, or if the sb crossmember is the same as the BB. would like to hear more myself......crazy AL

mikep · 11-05-2002, 12:03 PM

I know my motor sits back about 2 1/2 inches further than factory small blocks do. I went from big block to small block so I'd have to say they are not the same. Having said that I believe the 6 cylinder and the big block crossmembers ARE the same as they place the front of the bellhousing at the same point to allow for the longer motors. You might be in luck.

Canada20 · 11-05-2002, 12:36 PM

Longhorn; too bad the 73+ won't work; I have a feeling that's going to cut into how easily I'll find this thing

Mike; do you mean the engine crossmember or the one uder the bellhousing? My understanding is that the one under the bellhousing is different from the I-6 to the BB. It' be nice if I didn't have to move the trans, though.

Thanks for the replies,

Greg

I should mention my truck is a 2WD

crazy longhorn · 11-05-2002, 12:59 PM

the difference in placement between the 6 & the sb is right at 3 1/2". my 383 is set on 6 /250 stands, & fits very tight to the firewall(HEI dist fits, but with about 1 finger clearance tween the cap & firewall). Im not sure on the placement on the BB, but think it falls between the 6 & the sb. the bell crossmember is mounted on a downhill section of the frame, so needs to be changed when moving positions to keep the proper height at the rear of the eng. If you had a car trans , like the M20/21/22 muncie, or a BW T10.....you could use an auto crossmember & just drill the holes where needed in the frame. good luck.....crazy AL

mikep · 11-05-2002, 01:08 PM

If I get a chance later on today I'll measure from my transmission bellhousing to my radiator support and post it here. I'm not sure how much goo that will do you as my radiator support is a 68 and the 69-72's are different.

The engine crossmember is not the one I am talking about. Its the transmission that sits further back on my truck than a factory small block truck. Thats why I had to go with a long water pump and accesories because I was using big block motor mounts and a big block fan shroud and it wouldnt put the fan far enough forward even with a 2 inch spacer.

**Classic Heartbeat** · 11-05-2002, 01:17 PM

All 3 are different and are located in different spots on the frame. They are close but not close enough. If you are trying to mount things in what would have been stock possitions, with stock parts, you will need the correct crossmember for the aplication you are trying to achieve. WES www.ClassicHeartbeat.com

11-05-2002, 11:25 AM	#1
Canada20 Registered User Join Date: Jun 2001 Location: Calgary, Alberta, Canada Posts: 802	4-speed bellhousing crossmember; are BB and SB the same? Hey all. Not much to add the to topic line except explain what I'm hoping to do; swap a 454 in place of my 292 and I'd like to keep my 4-speed. Wes has mentioned that I'll need a different trans crossmember for this and I'm curious if I need one from a Big Block truck or are they the same for all V-8's? Also will a crossmember from a 73+ work? Thanks Greg __________________ No such thing as a stupid question, right?

11-05-2002, 12:03 PM	#3
mikep Used to have a truck Join Date: May 2002 Location: port orchard WA Posts: 1,552	I know my motor sits back about 2 1/2 inches further than factory small blocks do. I went from big block to small block so I'd have to say they are not the same. Having said that I believe the 6 cylinder and the big block crossmembers ARE the same as they place the front of the bellhousing at the same point to allow for the longer motors. You might be in luck. __________________ No truck :-(

11-05-2002, 12:36 PM	#4
Canada20 Registered User Join Date: Jun 2001 Location: Calgary, Alberta, Canada Posts: 802	Longhorn; too bad the 73+ won't work; I have a feeling that's going to cut into how easily I'll find this thing Mike; do you mean the engine crossmember or the one uder the bellhousing? My understanding is that the one under the bellhousing is different from the I-6 to the BB. It' be nice if I didn't have to move the trans, though. Thanks for the replies, Greg I should mention my truck is a 2WD __________________ No such thing as a stupid question, right? Last edited by Canada20; 11-05-2002 at 12:54 PM.

11-05-2002, 01:08 PM	#6
mikep Used to have a truck Join Date: May 2002 Location: port orchard WA Posts: 1,552	If I get a chance later on today I'll measure from my transmission bellhousing to my radiator support and post it here. I'm not sure how much goo that will do you as my radiator support is a 68 and the 69-72's are different. The engine crossmember is not the one I am talking about. Its the transmission that sits further back on my truck than a factory small block truck. Thats why I had to go with a long water pump and accesories because I was using big block motor mounts and a big block fan shroud and it wouldnt put the fan far enough forward even with a 2 inch spacer. __________________ No truck :-(

11-05-2002, 01:17 PM	#7
Classic Heartbeat Project Junkie! Fishing Poor!! Join Date: Dec 1999 Location: Olympia,Wa. 98512 Posts: 10,766	All 3 are different and are located in different spots on the frame. They are close but not close enough. If you are trying to mount things in what would have been stock possitions, with stock parts, you will need the correct crossmember for the aplication you are trying to achieve. WES 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

11-05-2002, 11:38 AM	#2
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,402	the 73 up crossmember wont work with your 4 spd truck trans. i know the inline & the sb bell crossmembers are different, & you will need the BB stands & eng mounts......but Im not sure about placement on the BB, or if the sb crossmember is the same as the BB. would like to hear more myself......crazy AL

11-05-2002, 12:59 PM	#5
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,402	the difference in placement between the 6 & the sb is right at 3 1/2". my 383 is set on 6 /250 stands, & fits very tight to the firewall(HEI dist fits, but with about 1 finger clearance tween the cap & firewall). Im not sure on the placement on the BB, but think it falls between the 6 & the sb. the bell crossmember is mounted on a downhill section of the frame, so needs to be changed when moving positions to keep the proper height at the rear of the eng. If you had a car trans , like the M20/21/22 muncie, or a BW T10.....you could use an auto crossmember & just drill the holes where needed in the frame. good luck.....crazy AL



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