67 GMC C10 motor conversion problem - The 1947 - Present Chevrolet & GMC Truck Message Board Network

natestep · 05-25-2016, 10:55 AM

I have a 67 GMC C10 that had a 292 with a power glide. I have put a 350/350 in it and I have all kinds of problems. I bought the V8 engine stands due to reading on here that I would need them due to the offset on the 292. I bolted my motor and transmission together and bolted the transmission mount to the cross member. When I let the motor down to the motor stands in the front holes my motor is about two inches back. My stock shift linkage appears to be lined up with the transmission perfectly. I ended up trying a later set of motor mounts on like an 80 model but my distributed is hitting the firewall before my cab mounts line up and the seem at the floor pan is hitting the bell housing. It appears that my cross member need moved up but that would throw my shift linkage off and it would have to be moved. I have about an inch or so play where the front yolk of my driveshaft comes out of my transmission so that looks right. All the post on here that I have read don't say anything about moving the crossmember but just a bolt in deal. The only thing I can figure is a turbo 350 is shorter than a glide. I have been a mechanic for about 20 years and it's driving me nuts to not see where the problem is. Please help!

**LockDoc** · 05-25-2016, 11:09 AM

Quote:

Originally Posted by natestep

I have a 67 GMC C10 that had a 292 with a power glide. I have put a 350/350 in it and I have all kinds of problems. I bought the V8 engine stands due to reading on here that I would need them due to the offset on the 292. I bolted my motor and transmission together and bolted the transmission mount to the cross member. When I let the motor down to the motor stands in the front holes my motor is about two inches back. My stock shift linkage appears to be lined up with the transmission perfectly. I ended up trying a later set of motor mounts on like an 80 model but my distributed is hitting the firewall before my cab mounts line up and the seem at the floor pan is hitting the bell housing. It appears that my cross member need moved up but that would throw my shift linkage off and it would have to be moved. I have about an inch or so play where the front yolk of my driveshaft comes out of my transmission so that looks right. All the post on here that I have read don't say anything about moving the crossmember but just a bolt in deal. The only thing I can figure is a turbo 350 is shorter than a glide. I have been a mechanic for about 20 years and it's driving me nuts to not see where the problem is. Please help!

The rear set of holes in the frame are for the I6 engine stands the front set of holes are for the V-8 engine stands. Use the front set and move the transmission cross member to match the trans mount. There may already be a set of holes in the frame to mount it, I am not familiar with the power glide rear cross member so you may have to get a 350 cross member. You will also have to use a 350 drive shaft and there seems to be two different LWB ones.

LockDoc

cruisinthe34 · 05-25-2016, 11:35 AM

Mount the engine first. Then position the transmission mount. I've always just measured for the drive shaft and had one made (or modified the old one if the new transmission was longer than the old one). You'll need to set the down angle of the motor as relates to the rearend Usually between 3 and 7 degrees.

**michael bustamante** · 05-25-2016, 11:58 AM

theres also two different length tail shaft housings on a 350 tranny. sounds like you might have a short shaft. once you scoot everything foward, you might have to get a longer drive shaft

natestep · 05-25-2016, 09:26 PM

Thanks for the replies fellows. I finally pulled the 80 type mount out and put the 67-72 V8 stands back in. The main problem was that the newer style mounts put to much angle on the motor causing the distributer to hit. When I changed the stands it lowered and leveled the motor more and the cab mounts would line up with the stands still in the wrong position. The stands landed in between the front and rear holes. I marked the holes and drilled new ones. The seam was still hitting the bell housing so I took a cut off wheel and a sanding disk and trimmed it about 1/4 inch. Everything worked great and the change saved a ton of work. I still have about a inch of play between the distributer and the firewall. I live in a rural area and the closest drive shaft place is quite a ways from me. I'm happy with it.

05-25-2016, 10:55 AM	#1
natestep Registered User Join Date: Mar 2016 Location: Cave City Ar Posts: 6	67 GMC C10 motor conversion problem I have a 67 GMC C10 that had a 292 with a power glide. I have put a 350/350 in it and I have all kinds of problems. I bought the V8 engine stands due to reading on here that I would need them due to the offset on the 292. I bolted my motor and transmission together and bolted the transmission mount to the cross member. When I let the motor down to the motor stands in the front holes my motor is about two inches back. My stock shift linkage appears to be lined up with the transmission perfectly. I ended up trying a later set of motor mounts on like an 80 model but my distributed is hitting the firewall before my cab mounts line up and the seem at the floor pan is hitting the bell housing. It appears that my cross member need moved up but that would throw my shift linkage off and it would have to be moved. I have about an inch or so play where the front yolk of my driveshaft comes out of my transmission so that looks right. All the post on here that I have read don't say anything about moving the crossmember but just a bolt in deal. The only thing I can figure is a turbo 350 is shorter than a glide. I have been a mechanic for about 20 years and it's driving me nuts to not see where the problem is. Please help!

05-25-2016, 11:35 AM	#3
cruisinthe34 Registered User Join Date: Sep 2015 Location: Charleston, WV Posts: 228	Re: 67 GMC C10 motor conversion problem Mount the engine first. Then position the transmission mount. I've always just measured for the drive shaft and had one made (or modified the old one if the new transmission was longer than the old one). You'll need to set the down angle of the motor as relates to the rearend Usually between 3 and 7 degrees. __________________ Steve My Build Thread: http://67-72chevytrucks.com/vboard/s...=morning+glory 1971 C10 Inline 6 250 700R4 "Marlene" 1934 Chevrolet Master Sedan 350 700R4 "Iris" 1941 Ford 1/2 Ton 5.0 H.O Roller C-4 "Rose" 2019 Honda Ridgeline

05-25-2016, 11:58 AM	#4
michael bustamante Senior Member Join Date: Sep 2007 Location: Albuquerque NM Posts: 7,814	Re: 67 GMC C10 motor conversion problem theres also two different length tail shaft housings on a 350 tranny. sounds like you might have a short shaft. once you scoot everything foward, you might have to get a longer drive shaft __________________ 1967custom

05-25-2016, 09:26 PM	#5
natestep Registered User Join Date: Mar 2016 Location: Cave City Ar Posts: 6	Re: 67 GMC C10 motor conversion problem Thanks for the replies fellows. I finally pulled the 80 type mount out and put the 67-72 V8 stands back in. The main problem was that the newer style mounts put to much angle on the motor causing the distributer to hit. When I changed the stands it lowered and leveled the motor more and the cab mounts would line up with the stands still in the wrong position. The stands landed in between the front and rear holes. I marked the holes and drilled new ones. The seam was still hitting the bell housing so I took a cut off wheel and a sanding disk and trimmed it about 1/4 inch. Everything worked great and the change saved a ton of work. I still have about a inch of play between the distributer and the firewall. I live in a rural area and the closest drive shaft place is quite a ways from me. I'm happy with it.



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