V6 swap to V8- Few Questions - The 1947 - Present Chevrolet & GMC Truck Message Board Network

remist17 · 08-20-2010, 12:04 PM

I am replacing a tired V6 enginer for a 383 stroker in my 87 R10 Stepside.

Can anyone tell me if the transmission mount is different for these two motors. I know I have to relocated the motor mounts but hoping ot reuse the 400 trans and driveshaft.

remist17 · 08-20-2010, 08:06 PM

anyone?

cor86 · 08-20-2010, 11:47 PM

If you are reusing the tranny, it will not need a different mount, but should probably get a new one. The trans xmember will not move either. I cannot say for sure on moving the mount towers, but I would just go to the local yard and pick up a set from a V8 truck. Going that route will allow you to use the more common 4 bolt mounts, although only three bolts are used.

pugs · 08-21-2010, 08:34 AM

im guessing you are remove a 4.3 v6. i did it last yr with my 85 and i used the 400 trans and the mounts from the 4.3. i had to loosen up the mounts on the towers , dropped in the v8 and tightened everything up, just dont forget to have the correct flexplate to both up to the 400 trans. i actually had to move the towers forward and drill one new per side did this in a few hours but then i had pulled the front clip off to make it easier

remist17 · 08-21-2010, 12:51 PM

Quote:

Originally Posted by pugs

im guessing you are remove a 4.3 v6. i did it last yr with my 85 and i used the 400 trans and the mounts from the 4.3. i had to loosen up the mounts on the towers , dropped in the v8 and tightened everything up, just dont forget to have the correct flexplate to both up to the 400 trans. i actually had to move the towers forward and drill one new per side did this in a few hours but then i had pulled the front clip off to make it easier

what tooth pattern is needed for a 400. Does it diifer from a 350?

pugs · 08-22-2010, 02:18 PM

i donr remember what tooth flexplate it was, but im thinking a 180 somewhere around there. the diameter of the both pattern on the converter it bigger. now im not sure but pendeing on the year engine u are using. meaning a 1 peice rear main with the smaller bolt pattern on the crank, you could use the stock flexplate

pugs · 08-22-2010, 02:21 PM

oh and you will need a V8 y-pipe for stock exhaust as the stock v6 ends that bolt to the manifolds have a slight curve and wont seal properly

remist17 · 08-24-2010, 11:44 AM

running a 1968 327 block bored .030 over.(383) two piece rear main, and running dual exhaust.

I will count the flex plate that is on there and see how many teeth and then see whats on the one I have for the 350.

08-20-2010, 12:04 PM	#1
remist17 Registered User Join Date: Jul 2009 Location: PA Posts: 406	V6 swap to V8- Few Questions I am replacing a tired V6 enginer for a 383 stroker in my 87 R10 Stepside. Can anyone tell me if the transmission mount is different for these two motors. I know I have to relocated the motor mounts but hoping ot reuse the 400 trans and driveshaft. __________________ 2013 Chevy Silverado, Z71, 5.3L, 4 door 2005 Chevy Silverado, Z71, 5.3L, 4 door, 3.40 Support the Troops.

08-20-2010, 08:06 PM	#2
remist17 Registered User Join Date: Jul 2009 Location: PA Posts: 406	Re: V6 swap to V8- Few Questions anyone? __________________ 2013 Chevy Silverado, Z71, 5.3L, 4 door 2005 Chevy Silverado, Z71, 5.3L, 4 door, 3.40 Support the Troops.

08-20-2010, 11:47 PM	#3
cor86 Registered User Join Date: Mar 2009 Location: Warsaw, IN Posts: 93	Re: V6 swap to V8- Few Questions If you are reusing the tranny, it will not need a different mount, but should probably get a new one. The trans xmember will not move either. I cannot say for sure on moving the mount towers, but I would just go to the local yard and pick up a set from a V8 truck. Going that route will allow you to use the more common 4 bolt mounts, although only three bolts are used.

08-21-2010, 08:34 AM	#4
pugs Registered User Join Date: Mar 2003 Location: Hamburg Pa Posts: 1,153	Re: V6 swap to V8- Few Questions im guessing you are remove a 4.3 v6. i did it last yr with my 85 and i used the 400 trans and the mounts from the 4.3. i had to loosen up the mounts on the towers , dropped in the v8 and tightened everything up, just dont forget to have the correct flexplate to both up to the 400 trans. i actually had to move the towers forward and drill one new per side did this in a few hours but then i had pulled the front clip off to make it easier __________________ I don't do thing cuz I can, I do it cuz someone told me it couldn't be done...

08-22-2010, 02:18 PM	#6
pugs Registered User Join Date: Mar 2003 Location: Hamburg Pa Posts: 1,153	Re: V6 swap to V8- Few Questions i donr remember what tooth flexplate it was, but im thinking a 180 somewhere around there. the diameter of the both pattern on the converter it bigger. now im not sure but pendeing on the year engine u are using. meaning a 1 peice rear main with the smaller bolt pattern on the crank, you could use the stock flexplate __________________ I don't do thing cuz I can, I do it cuz someone told me it couldn't be done...

08-22-2010, 02:21 PM	#7
pugs Registered User Join Date: Mar 2003 Location: Hamburg Pa Posts: 1,153	Re: V6 swap to V8- Few Questions oh and you will need a V8 y-pipe for stock exhaust as the stock v6 ends that bolt to the manifolds have a slight curve and wont seal properly __________________ I don't do thing cuz I can, I do it cuz someone told me it couldn't be done...

08-24-2010, 11:44 AM	#8
remist17 Registered User Join Date: Jul 2009 Location: PA Posts: 406	Re: V6 swap to V8- Few Questions running a 1968 327 block bored .030 over.(383) two piece rear main, and running dual exhaust. I will count the flex plate that is on there and see how many teeth and then see whats on the one I have for the 350. __________________ 2013 Chevy Silverado, Z71, 5.3L, 4 door 2005 Chevy Silverado, Z71, 5.3L, 4 door, 3.40 Support the Troops.



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