Bolting 205 adapter plate to crossmember--what size bolts to use? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

1969k10stepside · 05-20-2007, 01:52 PM

Ok,so I'm getting close (as in between now and next week) to bolting the motor,tranny,and t-case in the 71 shortbed.Now,the truck didn't have the drivetrain,or the bolts so I have no clue what size of bolts to use.
So...I think the bolts that go in the side of the 205 for the "torque bracket" are 5/8'' coarse thread, about 1 1/4'' long...correct?
What size bolts do I use that go in the bottom that connect the crossmember to the t-case?
Thanks,
Dustin

JAKES 68GMC · 05-20-2007, 06:39 PM

They are fairly long, like 3 1/2" thread maybe?, and they are 5/8" coarse thread. I could go pull one out and measure it for you, but I'm not that kind of guy.

eedgell · 05-22-2007, 05:59 PM

All the 205's I have been around are: 1 inch long x 5/8 on the torque bracket, and 3 inch long x 1/2 on the main mounts. All course threads.

1969k10stepside · 05-23-2007, 07:07 PM

Thanks guys.I just bought some bolts like mentioned above and they worked...Now I have a transfer case to bolt in friday...

JAKES 68GMC · 05-24-2007, 07:13 PM

Wait, aren't the crossmember bolts 5/8" thread as well? or do they have a 5/8" bolt head? Can't remember, been too long.

1969k10stepside · 05-24-2007, 07:48 PM

I bought the size eedgell posted and they seemed to work.

eedgell · 05-25-2007, 12:18 AM

3/4 and 15/16 head size.

msgross · 05-25-2007, 08:14 AM

I don't think my T-case bolted to a crossmember, only torque arm. I know the transmission bolted to it's crossmember, My T-case crossmember has a skid plate rivetted to it. It's a 221 Rockwell though so it might be different.

1969k10stepside · 05-25-2007, 11:25 AM

Mine don't either.....It bolts to the adapter plate which bolts to the crossmember.I'd have to look at my rockwell t case I have,I dont remember how it mounts.

1969k10stepside · 05-25-2007, 01:59 PM

Well,I got the transfer case in....the bolts were the right kind but the ones that bolt in the adapter werent long enough.Luckily I found one to work for now but I'm going to have to get some longer bolts eventually

1969k10stepside · 05-25-2007, 09:24 PM

Well...I managed to find some grade 8 bolts the right thread,and right size to use so now the transfer case is completely bolted down....next is the tranny and motor

eedgell · 05-26-2007, 04:45 PM

3 inch long 1/2 bolts were not long enough? What did you have to use?

1969k10stepside · 05-26-2007, 07:21 PM

I used ones close to 4" long.They stick out of the adapter,but they work.Should the t-case have room to move forward and back some while its bolted down,I think it should have some room to move,but how much?

eedgell · 05-26-2007, 07:41 PM

Wow! you must have some thick mounts or something. The T-case sould be able to move for and aft but not much more than the cross member allows. The cross member should bolt to the adapter with little deflection.

1969k10stepside · 05-27-2007, 06:47 PM

Yes,the mounts are thick,but the bolts do stick out of the adapter a lot.
I was out in the shop today while it rained and the transfer case all bolted down moves forward and back about 1/2-3/4"...to much?

eedgell · 05-28-2007, 12:27 PM

Are you bolted to your torque bracket?

1969k10stepside · 05-28-2007, 02:42 PM

Yep

eedgell · 05-28-2007, 03:04 PM

You should be good. You need some give when you install the engine and "suck" everything up tight. 1/2 inch is the world sometimes!

05-20-2007, 01:52 PM	#1
1969k10stepside Registered User Join Date: Mar 2006 Location: USA Posts: 21,020	Bolting 205 adapter plate to crossmember--what size bolts to use? Ok,so I'm getting close (as in between now and next week) to bolting the motor,tranny,and t-case in the 71 shortbed.Now,the truck didn't have the drivetrain,or the bolts so I have no clue what size of bolts to use. So...I think the bolts that go in the side of the 205 for the "torque bracket" are 5/8'' coarse thread, about 1 1/4'' long...correct? What size bolts do I use that go in the bottom that connect the crossmember to the t-case? Thanks, Dustin

05-20-2007, 06:39 PM	#2
JAKES 68GMC Aluminum slot wheels rule... Join Date: Jan 2006 Location: Maine Posts: 6,212	Re: Bolting 205 to crossmember--what size bolts to use? They are fairly long, like 3 1/2" thread maybe?, and they are 5/8" coarse thread. I could go pull one out and measure it for you, but I'm not that kind of guy.

05-22-2007, 05:59 PM	#3
eedgell It's the air up here Join Date: Mar 2007 Location: Western Colorado Posts: 710	Re: Bolting 205 to crossmember--what size bolts to use? All the 205's I have been around are: 1 inch long x 5/8 on the torque bracket, and 3 inch long x 1/2 on the main mounts. All course threads. __________________ 1971 cheyenne k10 4 speed np 205 454 BB factory a/c Never drink down stream of the herd! Eric

05-23-2007, 07:07 PM	#4
1969k10stepside Registered User Join Date: Mar 2006 Location: USA Posts: 21,020	Re: Bolting 205 to crossmember--what size bolts to use? Thanks guys.I just bought some bolts like mentioned above and they worked...Now I have a transfer case to bolt in friday...

05-24-2007, 07:13 PM	#5
JAKES 68GMC Aluminum slot wheels rule... Join Date: Jan 2006 Location: Maine Posts: 6,212	Re: Bolting 205 to crossmember--what size bolts to use? Wait, aren't the crossmember bolts 5/8" thread as well? or do they have a 5/8" bolt head? Can't remember, been too long.

05-24-2007, 07:48 PM	#6
1969k10stepside Registered User Join Date: Mar 2006 Location: USA Posts: 21,020	Re: Bolting 205 to crossmember--what size bolts to use? I bought the size eedgell posted and they seemed to work.

05-25-2007, 12:18 AM	#7
eedgell It's the air up here Join Date: Mar 2007 Location: Western Colorado Posts: 710	Re: Bolting 205 to crossmember--what size bolts to use? 3/4 and 15/16 head size. __________________ 1971 cheyenne k10 4 speed np 205 454 BB factory a/c Never drink down stream of the herd! Eric

05-25-2007, 08:14 AM	#8
msgross Registered User Join Date: Jul 2006 Location: Central PA Posts: 12,201	Re: Bolting 205 to crossmember--what size bolts to use? I don't think my T-case bolted to a crossmember, only torque arm. I know the transmission bolted to it's crossmember, My T-case crossmember has a skid plate rivetted to it. It's a 221 Rockwell though so it might be different. __________________ The Garage: 1968 K-10 SWB - "Project Money Pit" 1996 Z-71 - "huntin rig" 1969 C-10 LWB (SOLD) "Project flip that truck or else" 1993 Passport, F@rd 1-ton (SOLD)"Project Cousin Eddie" My Garage Build "The 1,000 footer"

05-25-2007, 11:25 AM	#9
1969k10stepside Registered User Join Date: Mar 2006 Location: USA Posts: 21,020	Re: Bolting 205 to crossmember--what size bolts to use? Mine don't either.....It bolts to the adapter plate which bolts to the crossmember.I'd have to look at my rockwell t case I have,I dont remember how it mounts.

05-25-2007, 01:59 PM	#10
1969k10stepside Registered User Join Date: Mar 2006 Location: USA Posts: 21,020	Re: Bolting 205 to crossmember--what size bolts to use? Well,I got the transfer case in....the bolts were the right kind but the ones that bolt in the adapter werent long enough.Luckily I found one to work for now but I'm going to have to get some longer bolts eventually

05-25-2007, 09:24 PM	#11
1969k10stepside Registered User Join Date: Mar 2006 Location: USA Posts: 21,020	Re: Bolting 205 adapter plate to crossmember--what size bolts to use? Well...I managed to find some grade 8 bolts the right thread,and right size to use so now the transfer case is completely bolted down....next is the tranny and motor

05-26-2007, 04:45 PM	#12
eedgell It's the air up here Join Date: Mar 2007 Location: Western Colorado Posts: 710	Re: Bolting 205 adapter plate to crossmember--what size bolts to use? 3 inch long 1/2 bolts were not long enough? What did you have to use? __________________ 1971 cheyenne k10 4 speed np 205 454 BB factory a/c Never drink down stream of the herd! Eric

05-26-2007, 07:21 PM	#13
1969k10stepside Registered User Join Date: Mar 2006 Location: USA Posts: 21,020	Re: Bolting 205 adapter plate to crossmember--what size bolts to use? I used ones close to 4" long.They stick out of the adapter,but they work.Should the t-case have room to move forward and back some while its bolted down,I think it should have some room to move,but how much? Last edited by 1969k10stepside; 05-26-2007 at 07:22 PM.

05-26-2007, 07:41 PM	#14
eedgell It's the air up here Join Date: Mar 2007 Location: Western Colorado Posts: 710	Re: Bolting 205 adapter plate to crossmember--what size bolts to use? Wow! you must have some thick mounts or something. The T-case sould be able to move for and aft but not much more than the cross member allows. The cross member should bolt to the adapter with little deflection. __________________ 1971 cheyenne k10 4 speed np 205 454 BB factory a/c Never drink down stream of the herd! Eric

05-27-2007, 06:47 PM	#15
1969k10stepside Registered User Join Date: Mar 2006 Location: USA Posts: 21,020	Re: Bolting 205 adapter plate to crossmember--what size bolts to use? Yes,the mounts are thick,but the bolts do stick out of the adapter a lot. I was out in the shop today while it rained and the transfer case all bolted down moves forward and back about 1/2-3/4"...to much? Last edited by 1969k10stepside; 05-27-2007 at 06:48 PM.



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05-28-2007, 12:27 PM	#16
eedgell It's the air up here Join Date: Mar 2007 Location: Western Colorado Posts: 710	Re: Bolting 205 adapter plate to crossmember--what size bolts to use? Are you bolted to your torque bracket? __________________ 1971 cheyenne k10 4 speed np 205 454 BB factory a/c Never drink down stream of the herd! Eric

05-28-2007, 02:42 PM	#17
1969k10stepside Registered User Join Date: Mar 2006 Location: USA Posts: 21,020	Re: Bolting 205 adapter plate to crossmember--what size bolts to use? Yep

05-28-2007, 03:04 PM	#18
eedgell It's the air up here Join Date: Mar 2007 Location: Western Colorado Posts: 710	Re: Bolting 205 adapter plate to crossmember--what size bolts to use? You should be good. You need some give when you install the engine and "suck" everything up tight. 1/2 inch is the world sometimes! __________________ 1971 cheyenne k10 4 speed np 205 454 BB factory a/c Never drink down stream of the herd! Eric

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