Few questions (rockwell T-221 swap and tranny) - The 1947 - Present Chevrolet & GMC Truck Message Board Network

*FUNMUDDER* · 01-01-2006, 12:39 PM

Hello,
First of all, I'd like to know what my 68 GMC has for a transmission. It has numbers on the top cover but they don't say the make of the tranny, just GM numbers. Reverse is next to 4th gear, if that helps.
Second, I am thinking of a transfer case swap. I read in a previous Rockwell t-case thread that a Sm465 with a Rockwell tagging along is the same length as a 465 with an NP205. But another thread that I started said I had to move the t-case crossmember back and re-do the driveshafts.
So heres my other Q: if I could get a complete parts-truck with a NP 205, could I bolt the t-case and driveshafts right in, move the crossmember back, and be all set? Are the trannys the same? Thank you for responces.

*FUNMUDDER* · 01-01-2006, 06:04 PM

Ttt

1969 GMC · 01-02-2006, 02:44 AM

when I converted mine (although the project has since frozen) I had to move the crossmember back perhaps 1.5" iirc. I might have been able to get away with the stock 2 pc driveshaft if i shoved the splines all the way into each other, but you'd need the front shaft lengthened. I'm guessing my thread was one of the ones you found.

LONGHAIR · 01-02-2006, 03:58 PM

Before you ask where it went..............I removed the duplicate thread. Please don't make duplicates, it's in the rules.

*FUNMUDDER* · 01-02-2006, 10:07 PM

Sorry about that. Won't happen again.

**'68OrangeSunshine** · 01-03-2006, 08:01 AM

Jake:
If the tranny has the casting #: 3901127 it's an SM465, and it's a Muncie. Not so much a make, as a town where GM had a transmission plant. [Muncie, Indiana; Saganaw, Michigan].

01-01-2006, 12:39 PM	#1
FUNMUDDER Account Suspended Join Date: Jun 2005 Location: Maine Posts: 427	67-72 QUESTIONS (Rockwell T-221 swap+tranny Q) Hello, First of all, I'd like to know what my 68 GMC has for a transmission. It has numbers on the top cover but they don't say the make of the tranny, just GM numbers. Reverse is next to 4th gear, if that helps. Second, I am thinking of a transfer case swap. I read in a previous Rockwell t-case thread that a Sm465 with a Rockwell tagging along is the same length as a 465 with an NP205. But another thread that I started said I had to move the t-case crossmember back and re-do the driveshafts. So heres my other Q: if I could get a complete parts-truck with a NP 205, could I bolt the t-case and driveshafts right in, move the crossmember back, and be all set? Are the trannys the same? Thank you for responces. Last edited by FUNMUDDER; 01-01-2006 at 11:36 PM.

01-01-2006, 06:04 PM	#2
FUNMUDDER Account Suspended Join Date: Jun 2005 Location: Maine Posts: 427	Re: Few questions (rockwell T-221 swap and tranny) Ttt

01-02-2006, 02:44 AM	#3
1969 GMC Registered User Join Date: Feb 2003 Location: The Rubber City Posts: 5,498	Re: Few questions (rockwell T-221 swap and tranny) when I converted mine (although the project has since frozen) I had to move the crossmember back perhaps 1.5" iirc. I might have been able to get away with the stock 2 pc driveshaft if i shoved the splines all the way into each other, but you'd need the front shaft lengthened. I'm guessing my thread was one of the ones you found. __________________ 1969 GMC K2500 1996 Honda Accord 2007 Kawasaki KLR 650

01-02-2006, 03:58 PM	#4
LONGHAIR just can't cover up my redneck Join Date: May 2004 Location: Columbus OH Posts: 11,414	Re: Few questions (rockwell T-221 swap and tranny) Before you ask where it went..............I removed the duplicate thread. Please don't make duplicates, it's in the rules. Last edited by LONGHAIR; 01-03-2006 at 08:21 PM.

01-02-2006, 10:07 PM	#5
FUNMUDDER Account Suspended Join Date: Jun 2005 Location: Maine Posts: 427	Re: Few questions (rockwell T-221 swap and tranny) Sorry about that. Won't happen again.

01-03-2006, 08:01 AM	#6
'68OrangeSunshine Senior Member Join Date: Feb 2002 Location: Tucson, AZ USA Posts: 7,513	Re: Few questions (rockwell T-221 swap and tranny) Jake: If the tranny has the casting #: 3901127 it's an SM465, and it's a Muncie. Not so much a make, as a town where GM had a transmission plant. [Muncie, Indiana; Saganaw, Michigan]. __________________ Every 25 years I like to rebuild that 292, whether it needs it or not. Last edited by '68OrangeSunshine; 01-03-2006 at 08:05 AM.



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