bbc sm465 question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Wildstreak · 06-11-2012, 07:09 PM

Im doin a bbc swap into a 68 4x4 I have a sm465 with a np205 from a small block I would like to use, do I need a new bellhouse or is the bellhouse the same for both?

rcbildr · 06-11-2012, 09:01 PM

IIRC the bellhousing should be the same for both.

snj8198 · 06-12-2012, 12:57 AM

yep, bolt em up. your z-bar may be different. look into that perhaps. otherwise there is no issue.

have fun with the new big block!

OLDCHEV4X4 · 06-12-2012, 08:33 AM

Bell will work.
I have heard of problems with valve covers hitting the fire wall and the frame having to be notched for exhaust manifolds/headers. I've personally never did the swap so i have no 1st hand experience.

snj8198 · 06-12-2012, 09:48 AM

Quote:

Originally Posted by OLDCHEV4X4

Bell will work.
I have heard of problems with valve covers hitting the fire wall and the frame having to be notched for exhaust manifolds/headers. I've personally never did the swap so i have no 1st hand experience.

oh ya, thanks for the reminder. Some have valve cover clearance issues and some do not. If you plan to run full roller rockers you'll need to use tall valve covers to clear them, this is where most people run into firewall clearance when converting to a big block. When i do it again i will move the motor to the forward set of mounting holes on the frame and extend the drive shaft. This will alleviate a lot of the clearance issues with both the covers as well as the tight fit for an HEI dizzy. -steve

06-11-2012, 07:09 PM	#1
Wildstreak "something witty here" Join Date: Apr 2009 Location: Salmo, B.C, Canada Posts: 966	bbc sm465 question Im doin a bbc swap into a 68 4x4 I have a sm465 with a np205 from a small block I would like to use, do I need a new bellhouse or is the bellhouse the same for both? __________________ 57 chevy 4x4 70 swb fleetside 4x4 68 burb 2wd: 71 burb 2wd: 350 4spd 71 lwb fleetside 4x4: 350/sm465/205/3.07 eaton posi rear 72 lwb fleetside Cheyenne 454/th400 1991 GMC V3500 CC 4x4

06-11-2012, 09:01 PM	#2
rcbildr Registered User Join Date: Sep 2000 Location: Gold Bar, WA Posts: 1,216	Re: bbc sm465 question IIRC the bellhousing should be the same for both. __________________ My Projects: 1960 GMC 1/2ton with 305 V6 (daily driver) 1963 Chevy 1/2ton 2wd...converting to 4x4 1967 Suburban 1/2ton 2wd My Girlfriends Projects 1985 Chevy Suburban 3/4ton 4x4 with 6.2L diesel, 4" lift, converted to TH-400, Warn Premium manual hubs, & Wildcat 315/75/R16 tires. (daily driver) 1978 Camaro Type LT with a Marine 350 & vortec heads, Rochester Carb, & roller cam 1978 Camaro Z28

06-12-2012, 12:57 AM	#3
snj8198 Registered User Join Date: Feb 2007 Location: Star Valley, WY Posts: 2,038	Re: bbc sm465 question yep, bolt em up. your z-bar may be different. look into that perhaps. otherwise there is no issue. have fun with the new big block! __________________ Steve 1971 GMC Longbox. Full Roller Stroker 489 w/ FiTech EFI, Chris Straub Cam/NV4500/205/D60/14B w. Grizzly Locker and 4.11's. 2" Lift on 33's

06-12-2012, 08:33 AM	#4
OLDCHEV4X4 Registered User Join Date: Apr 2000 Location: Chester County PA, USA Posts: 1,228	Re: bbc sm465 question Bell will work. I have heard of problems with valve covers hitting the fire wall and the frame having to be notched for exhaust manifolds/headers. I've personally never did the swap so i have no 1st hand experience. __________________ 72 k/10 short wideside 72 k/5 Blazer 72 K/5 Blazer - obstacle course racer 72 custom/10 8' bed 70 K/5 Blazer 67 C-30 GMC Flat bed 86 GMC K2500 Plow Truck 85 GMC K3500 84 M1008 85 M1008 77 G30 Motor Home 72 Sears 12hp Tractor Glenmoore, Pennsylvania



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