3spd to auto swap - The 1947 - Present Chevrolet & GMC Truck Message Board Network

72shadetree · 07-11-2002, 11:15 PM

changing 3spd to auto on the 72.finall got 3spd crossmember out got a auto xmember from anther72 but when i bolted it to trans the xmember and frame holes dont come close there is several sets of holes in frame but all about 2inches off.drilling new holes in frame is no problem but i thought this was a direct bolt in.anybody else have this problem buy the way im running a 350/th350 combo with the motor in the correct foward holes

72sleeper · 07-11-2002, 11:24 PM

what r u doin with your old tranny and clutch and stuff along those lines??? and ifyou sellin em are they in good shape or what??

da-burb · 07-11-2002, 11:29 PM

I did this swap in my 72 C10. It always had a V-8 in it, but all the holes were right there where they were supposed to be. Any chance you got a th400 cross member? I need to put them side by side one of these days to see what differences there are.

72shadetree · 07-11-2002, 11:31 PM

sorry already got rid of it.this dummy wanted a 3spd so i traded it for a 70 chevy pu with 307 and guess what a 3spd (go figure) and i drove it home.was going to use it for parts but its to good to part so my 12yr old son going to fix it up.still cant figure out why he would trade a running truck with 3spd for a 3spd his loss my gain hehe

72shadetree · 07-11-2002, 11:35 PM

the 400 xmember could be possible but i thought they would be the same.the only thing i can think it may be is i got a smallblock in a bb truck with the bb moter stands

gaddman · 07-12-2002, 03:12 PM

Just a couple of things...

Are you using 6cyl or 8cyl engine brackets? They look very much alike, but will make a difference in the placement of the driveline.

Or...there are 2 sets of holes in the frame for the engine brackets. Could you move them to the other holes and get the tranny crossmember lined up?

I have a 350/350, using v8 brackets in rear set of holes (6 cyl position) and I had to drill some holes in the tranny crossmember. If I moved up the to the V8 holes with the engine brackets, or used 6cyl brackets, I think it would have bolted up without drilling. I like the idea of having the engine a little further back for better handling. But the 6cyl brackets seemed to move it too far back. I like the combo that I have now, but the driveshaft does need to be shortened.

Here's some pics....and good luck!

SWINGSAX68 · 07-12-2002, 04:04 PM

the only draw back to my 307 in the V6 mounting is that the distributer is a little tight fitting. against the fire wall, and I did have to get the shaft shortened.

I 've got two three speed columns for sale!!!!CHEAP!!!!!!!AND A THREE SPEED TRANNY!!!!!!!!

72shadetree · 07-12-2002, 04:32 PM

the motor is in the foward v8 holes on bb towers.thx

**Tim Christian** · 07-12-2002, 10:10 PM

Hey Shadetree I say the Big Block motor mounts are you problem. I have never had that problem.

72shadetree · 07-12-2002, 10:52 PM

thx alot keepem coming got to leave out on truck tonight for monday morning i ca ill check back in a couuple weeks

07-11-2002, 11:15 PM	#1
72shadetree KEEP ON TRUCKING Join Date: Sep 2000 Location: martinsville va Posts: 2,563	3spd to auto swap changing 3spd to auto on the 72.finall got 3spd crossmember out got a auto xmember from anther72 but when i bolted it to trans the xmember and frame holes dont come close there is several sets of holes in frame but all about 2inches off.drilling new holes in frame is no problem but i thought this was a direct bolt in.anybody else have this problem buy the way im running a 350/th350 combo with the motor in the correct foward holes __________________ 72 cheyenne 2wd lwb 71 k20 sons bassett va

07-11-2002, 11:24 PM	#2
72sleeper []D [] []v[] []D Join Date: Dec 2001 Location: h'vegas,TN,USA Posts: 78	what r u doin with your old tranny and clutch and stuff along those lines??? and ifyou sellin em are they in good shape or what?? __________________ Clint 72 c'10 350ci/400hp sleeper forever

07-11-2002, 11:29 PM	#3
da-burb "Ochre Ogre" Join Date: Apr 2000 Location: Springfield, MN Posts: 3,558	I did this swap in my 72 C10. It always had a V-8 in it, but all the holes were right there where they were supposed to be. Any chance you got a th400 cross member? I need to put them side by side one of these days to see what differences there are. __________________ Bowtie Truck Stop Inc. Mid-West GM Truck Restoration Parts Supplier Your Key Parts, Auto Metal Direct, Dynacorn, and Goodmark dealer. like us @ www.facebook.com/BowtieTruckStop 1971 C-10 Suburban (Ochre) 1971 K-10 Suburban (Ochre) 1972 C-10 Suburban (Ochre) 1972 K-20 Suburban (Yellow- that just aint right!) Springfield, Minnesota 56087

07-11-2002, 11:31 PM	#4
72shadetree KEEP ON TRUCKING Join Date: Sep 2000 Location: martinsville va Posts: 2,563	sorry already got rid of it.this dummy wanted a 3spd so i traded it for a 70 chevy pu with 307 and guess what a 3spd (go figure) and i drove it home.was going to use it for parts but its to good to part so my 12yr old son going to fix it up.still cant figure out why he would trade a running truck with 3spd for a 3spd his loss my gain hehe __________________ 72 cheyenne 2wd lwb 71 k20 sons bassett va

07-11-2002, 11:35 PM	#5
72shadetree KEEP ON TRUCKING Join Date: Sep 2000 Location: martinsville va Posts: 2,563	the 400 xmember could be possible but i thought they would be the same.the only thing i can think it may be is i got a smallblock in a bb truck with the bb moter stands __________________ 72 cheyenne 2wd lwb 71 k20 sons bassett va

07-12-2002, 03:12 PM	#6
gaddman Registered User Join Date: Apr 2001 Location: Scottsburg, In Posts: 160	maybe motor brackets? Just a couple of things... Are you using 6cyl or 8cyl engine brackets? They look very much alike, but will make a difference in the placement of the driveline. Or...there are 2 sets of holes in the frame for the engine brackets. Could you move them to the other holes and get the tranny crossmember lined up? I have a 350/350, using v8 brackets in rear set of holes (6 cyl position) and I had to drill some holes in the tranny crossmember. If I moved up the to the V8 holes with the engine brackets, or used 6cyl brackets, I think it would have bolted up without drilling. I like the idea of having the engine a little further back for better handling. But the 6cyl brackets seemed to move it too far back. I like the combo that I have now, but the driveshaft does need to be shortened. Here's some pics....and good luck! __________________ Gaddman Scottsburg, In 67 SWB w/93 step bed 68 LWB Fleetside C10 Custom 50 Chevy 3600 74 Norton Commando 850 72 Norton Commando 750

07-12-2002, 04:04 PM	#7
SWINGSAX68 Now the others dig........ Join Date: May 2002 Location: San Antonio, TX Posts: 1,520	same here the only draw back to my 307 in the V6 mounting is that the distributer is a little tight fitting. against the fire wall, and I did have to get the shaft shortened. I 've got two three speed columns for sale!!!!CHEAP!!!!!!!AND A THREE SPEED TRANNY!!!!!!!! __________________ 68 Chevy C10 Stepside Black Primer 78 GMC Longbed White 09 Chevy Silverado Shortbed Granite Blue *LOOKING FOR A 67 4 DOOR IMPALA!!!Just like Sam and Dean Winchester!! 'Cause Mustangs are for p^#$ and you can fit a body in the trunk of a 67 Impala* MEMBER OF THE DRUM BRAKE CLUB Bachelor of Music in Jazz Studies Texas State University-San Marcos, TX Certified Music Educator I hope Mom is up there watching and being my Guardian Angel "I've got a fever.....and the only prescription.....IS MORE COW BELL" -The Legendary: Bruce Dickenson "F#$@ 'em up!!!!!!" -The Legendary: Rogelio Escobar TRUCKY LINKS** http://67-72chevytrucks.com/vboard/s...d.php?t=457750 http://67-72chevytrucks.com/vboard/s...d.php?t=461184 http://67-72chevytrucks.com/vboard/s...d.php?t=472848 http://67-72chevytrucks.com/vboard/s...d.php?t=417541 http://67-72chevytrucks.com/vboard/s...d.php?t=477788

07-12-2002, 04:32 PM	#8
72shadetree KEEP ON TRUCKING Join Date: Sep 2000 Location: martinsville va Posts: 2,563	the motor is in the foward v8 holes on bb towers.thx __________________ 72 cheyenne 2wd lwb 71 k20 sons bassett va

07-12-2002, 10:10 PM	#9
Tim Christian Senior Member Join Date: Dec 1999 Location: TN/VA Posts: 6,388	Hey Shadetree I say the Big Block motor mounts are you problem. I have never had that problem.

07-12-2002, 10:52 PM	#10
72shadetree KEEP ON TRUCKING Join Date: Sep 2000 Location: martinsville va Posts: 2,563	thx alot keepem coming got to leave out on truck tonight for monday morning i ca ill check back in a couuple weeks __________________ 72 cheyenne 2wd lwb 71 k20 sons bassett va



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