4x4 crossmember/ mount differences?? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

edman87 · 11-15-2006, 02:18 AM

I am putting a '84 sm465/ np208 in my 87 k5 replacing the 700r4/ np208. I need to know if the crossmember for the sm465 is different or just the adapter? I know the mount changed in 85 up to a 1 piece for auto and standard. My 87 crossmember sits waaay to high up- about 4". The trans to t-case adapter for the 700r has the mount flange almost even with the t-case circle, the sm465 adapter sits 4" lower.
So was the difference in the crossmember or the adapter?
Bty, I am trying to use a re-drilled 85up mount.
Any help/pics is appreciated.

rcbildr · 11-19-2006, 04:32 AM

I recently did this swap on my 85 Suburban, and I used an SM-465 from an 82 Blazer. If I understand what you are saying...sorry long night...the crossmember and adapters are different. You can't use the t-case adapter from the 700R4/NP-208 on the SM-465/NP-208. It sounds to me like your SM-465 has the "tall" adapter. If your stock crossmember looks like a W, it will not work with the manual transmission setup....the height is an issue. I even made an adater to get the bolt holes to line up, but then the front u-joint on the drive shaft hit a brace. I ended up buying a different crossmember. I'll try to get some pics tomorrow or the next day. Hope this helps.

edman87 · 11-19-2006, 10:47 AM

That would be my issue. A pic of your crossmember would be great. I don't know what crossmember I need is from.

edman87 · 11-19-2006, 12:44 PM

Ok, went to my spare parts pile and found a short(in height) sm465 to 208 adapter, I think it will work fine, I will know later today. I did not realize there was different adapters for different years, guess I know now. Glad I figured it out before building a crossmember or chopping up the stock one!

edman87 · 11-19-2006, 12:44 PM

BTW, if I would have never read your post, I would not have thought to look and see if there were differences. Thanks

rcbildr · 11-20-2006, 01:17 AM

I can't remember when they changed the adapters, but it gave me a headache for a while too. I have pics of my set up and can post them as soon as I get them on my computer. I had to do some work on my Burb before I left for work and ran out of time.

Glad to hear you got it figured out.

11-15-2006, 02:18 AM	#1
edman87 junk collector Join Date: Dec 2004 Location: above Baton Rouge, LA Posts: 693	4x4 crossmember/ mount differences?? I am putting a '84 sm465/ np208 in my 87 k5 replacing the 700r4/ np208. I need to know if the crossmember for the sm465 is different or just the adapter? I know the mount changed in 85 up to a 1 piece for auto and standard. My 87 crossmember sits waaay to high up- about 4". The trans to t-case adapter for the 700r has the mount flange almost even with the t-case circle, the sm465 adapter sits 4" lower. So was the difference in the crossmember or the adapter? Bty, I am trying to use a re-drilled 85up mount. Any help/pics is appreciated. __________________ '87/89/76 K5 in progress '99 K2500 short crew '91 camaro rs '98 jeep tj '52 willys cj3a

11-19-2006, 04:32 AM	#2
rcbildr Registered User Join Date: Sep 2000 Location: Gold Bar, WA Posts: 1,216	Re: 4x4 crossmember/ mount differences?? I recently did this swap on my 85 Suburban, and I used an SM-465 from an 82 Blazer. If I understand what you are saying...sorry long night...the crossmember and adapters are different. You can't use the t-case adapter from the 700R4/NP-208 on the SM-465/NP-208. It sounds to me like your SM-465 has the "tall" adapter. If your stock crossmember looks like a W, it will not work with the manual transmission setup....the height is an issue. I even made an adater to get the bolt holes to line up, but then the front u-joint on the drive shaft hit a brace. I ended up buying a different crossmember. I'll try to get some pics tomorrow or the next day. Hope this helps. __________________ 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

11-19-2006, 10:47 AM	#3
edman87 junk collector Join Date: Dec 2004 Location: above Baton Rouge, LA Posts: 693	Re: 4x4 crossmember/ mount differences?? That would be my issue. A pic of your crossmember would be great. I don't know what crossmember I need is from. __________________ '87/89/76 K5 in progress '99 K2500 short crew '91 camaro rs '98 jeep tj '52 willys cj3a

11-19-2006, 12:44 PM	#4
edman87 junk collector Join Date: Dec 2004 Location: above Baton Rouge, LA Posts: 693	Re: 4x4 crossmember/ mount differences?? Ok, went to my spare parts pile and found a short(in height) sm465 to 208 adapter, I think it will work fine, I will know later today. I did not realize there was different adapters for different years, guess I know now. Glad I figured it out before building a crossmember or chopping up the stock one! __________________ '87/89/76 K5 in progress '99 K2500 short crew '91 camaro rs '98 jeep tj '52 willys cj3a

11-19-2006, 12:44 PM	#5
edman87 junk collector Join Date: Dec 2004 Location: above Baton Rouge, LA Posts: 693	Re: 4x4 crossmember/ mount differences?? BTW, if I would have never read your post, I would not have thought to look and see if there were differences. Thanks __________________ '87/89/76 K5 in progress '99 K2500 short crew '91 camaro rs '98 jeep tj '52 willys cj3a

11-20-2006, 01:17 AM	#6
rcbildr Registered User Join Date: Sep 2000 Location: Gold Bar, WA Posts: 1,216	Re: 4x4 crossmember/ mount differences?? I can't remember when they changed the adapters, but it gave me a headache for a while too. I have pics of my set up and can post them as soon as I get them on my computer. I had to do some work on my Burb before I left for work and ran out of time. Glad to hear you got it figured out. __________________ 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



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