fitment isssues motor trans drive shaft 71 swb - The 1947 - Present Chevrolet & GMC Truck Message Board Network

tom71 · 10-08-2005, 03:19 PM

hello all i m having problems with my project i have a 71 swb truck and i put the motor, sbc and trans ,400 in today and the drive shaft seems short
the ,chassis is not the original ,not the one that the drive shaft came out of
i used the forward two motor stand holes on the chassis , i believed the rearward two are for a bbc the chassis is bagged and sitting on as low as it will go . so when i put the driveshaft in and try to bolt it to the diff it pulls completely out of the trans i believe it will hook up to the trans if i use the rear ward motor stand holes as well as the trans cross member holes but is this right? as i wrote i thought that the rear ward holes were for a bbc thanks for your imput , tom

**pjmoreland** · 10-08-2005, 03:36 PM

I'm not familiar with big block mounts, but I do know that the rear holes are used for inline 6 motor mount towers and the front holes are used for smallblock motor mount towers. The inline 6 towers are not the same as the smallblock towers. I'm guessing that your driveshaft was originally for an inline 6 motor. If you have the inline 6 towers, you can put them in the rear holes and mount a smallblock on them. You'd also have to slide the transmission crossmember back. Your driveshaft would probably work then. Your shifting linkage rod may be too short in this configuration. Also your fan will no longer be inside the shroud. What size motor do you have?

tom71 · 10-08-2005, 04:13 PM

Quote:

Originally Posted by pjmoreland

I'm not familiar with big block mounts, but I do know that the rear holes are used for inline 6 motor mount towers and the front holes are used for smallblock motor mount towers. The inline 6 towers are not the same as the smallblock towers. I'm guessing that your driveshaft was originally for an inline 6 motor. If you have the inline 6 towers, you can put them in the rear holes and mount a smallblock on them. You'd also have to slide the transmission crossmember back. Your driveshaft would probably work then. Your shifting linkage rod may be too short in this configuration. Also your fan will no longer be inside the shroud. What size motor do you have?

well the drive shaft was in a truck that had a 327 in it , i have a 350, if i use the rearward holes and pushe the trans cross member back how close will the fire wall be? willthere be a problem with installing an hei? thanks for your input

72wascal · 10-08-2005, 05:05 PM

The 350 and the 327 should bolt up in the same space. The 400 is longer than the 350 and should have to move the crossmember as mounting is a tad different. You will have to shorted the driveshaft to take up the slack between yoke and universal joint on the rearend. I plan to put a big block in my 72 next year and will need to move the BB forward a bit to accomodate the larger size trans. I currently have a 331 with HEI hooked to a T350 with no problems. Hope this helps.

Tx Firefighter · 10-09-2005, 06:02 AM

The front holes are for V8, both small and big block. The rear holes are for inline 6 engines. Like was said, the frame stands are different. If you decide to move the engine back onto the rear set of holes, you will need inline 6 frame stands. The HEI will be close to the firewall, but it will clear. You will still be able to R&R the distributor cap and even the whole distributor as needed. No need to alter the firewall.

Like was mentioned, your fan will no longer be inside the shroud where it should be.

By the way, there are several different frame stands...small block V8, 68-71 big block, 72 big block, 230/250 inline 6, and 292 inline 6.

I did an FAQ article on big block stands and mounts that anyone swapping to a big block should read. Just look in the FAQ section. There are good pictures and explanation of different mounts and options you have.

10-08-2005, 03:19 PM	#1
tom71 what happened to flint mi Join Date: Oct 2005 Location: san diego Posts: 436	fitment isssues motor trans drive shaft 71 swb hello all i m having problems with my project i have a 71 swb truck and i put the motor, sbc and trans ,400 in today and the drive shaft seems short the ,chassis is not the original ,not the one that the drive shaft came out of i used the forward two motor stand holes on the chassis , i believed the rearward two are for a bbc the chassis is bagged and sitting on as low as it will go . so when i put the driveshaft in and try to bolt it to the diff it pulls completely out of the trans i believe it will hook up to the trans if i use the rear ward motor stand holes as well as the trans cross member holes but is this right? as i wrote i thought that the rear ward holes were for a bbc thanks for your imput , tom

10-08-2005, 05:05 PM	#4
72wascal Hawaiian Member Join Date: Oct 2005 Location: Maui, Hawaii Posts: 28	Engine fitment The 350 and the 327 should bolt up in the same space. The 400 is longer than the 350 and should have to move the crossmember as mounting is a tad different. You will have to shorted the driveshaft to take up the slack between yoke and universal joint on the rearend. I plan to put a big block in my 72 next year and will need to move the BB forward a bit to accomodate the larger size trans. I currently have a 331 with HEI hooked to a T350 with no problems. Hope this helps.

10-09-2005, 06:02 AM	#5
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	The front holes are for V8, both small and big block. The rear holes are for inline 6 engines. Like was said, the frame stands are different. If you decide to move the engine back onto the rear set of holes, you will need inline 6 frame stands. The HEI will be close to the firewall, but it will clear. You will still be able to R&R the distributor cap and even the whole distributor as needed. No need to alter the firewall. Like was mentioned, your fan will no longer be inside the shroud where it should be. By the way, there are several different frame stands...small block V8, 68-71 big block, 72 big block, 230/250 inline 6, and 292 inline 6. I did an FAQ article on big block stands and mounts that anyone swapping to a big block should read. Just look in the FAQ section. There are good pictures and explanation of different mounts and options you have. __________________ I'm on the Instagram- @Gearhead_Kevin Last edited by Tx Firefighter; 10-09-2005 at 06:04 AM.

10-08-2005, 03:36 PM	#2
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 6,011	I'm not familiar with big block mounts, but I do know that the rear holes are used for inline 6 motor mount towers and the front holes are used for smallblock motor mount towers. The inline 6 towers are not the same as the smallblock towers. I'm guessing that your driveshaft was originally for an inline 6 motor. If you have the inline 6 towers, you can put them in the rear holes and mount a smallblock on them. You'd also have to slide the transmission crossmember back. Your driveshaft would probably work then. Your shifting linkage rod may be too short in this configuration. Also your fan will no longer be inside the shroud. What size motor do you have?



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