6 cylinder to 350 V-8

Discussion in '1967-1972' started by beach9618, Mar 17, 2005.

  1. beach9618

    beach9618 Member

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    I'm confused. I am putting a 350 V-8 with a th350 trans in my 72 c-10. Someone told me that I would have to change my current motor mounts (the 6 cylinder ones) for a pair of V-8 motor mounts and also to put the V-8 motor mounts in the forward frame mounting holes. I did this and everything seemed to fit pretty well even though the fan sits just inside the the radiator cowl which may cause cavitation. Anyway someone saw what I had done and told me the engine was way too far forward. So I decided to reinstall my 6 cylinder mounts (in the rear holes as original) and try the engine in that position. It works but it looks awfully close to the firewall now and with my HEI distributor I probably have less than 1/4" inch to the firewall. The top of the transmission is about 1/8" from the metal seam on the lower part of the firewall. Does anyone out there know for sure which way to mount this v-8?
    Any help would be appreciated.

    Thanks
    Jimx(

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    Last edited: Jan 25, 2011
  2. dvalentine

    dvalentine Charter Member

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    The last position that is closer to the firewall is the correct one.

    You CAN move the mounts 2 1/2 inches forward to gain added clearance at the firewall with no ill effects. You might run into exhaust header clearance problems in addition to the fan being too far forward.

    DV
     
  3. beach9618

    beach9618 Member

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    Thanks for the reply.
    Question. If I use the rear location I have to use the original 6 cylinder motor mount towers because the V-8 towers I bought will only fit in the forward mounting position. Of course the 2 top bolts fit in either position but the single bottom bolt only fits the rear position with the 6 cylinder mounts and only the front position with the V-8 mounts.
    So it seems like the front is the correct mounting spot. Am I missing something?

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    Last edited: Jan 25, 2011
  4. dvalentine

    dvalentine Charter Member

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    I don't know what V8 mounts you have. BUT, on my 64 when I moved the motor forward last year, I needed to drill out the lower bolt hole on the crossmember. On the 64 there was zero clearance between the HEI and the firewall. Removing a distributor cap was a 20 minute, expletive deleted rich, pain... So I decided to move it up.

    I am not positive what the differences are between the early 60's and your year, but everything I know about motor mount perches I learned from our friend Van Pershing's site.

    http://www.geocities.com/vapershing/perches.html

    DV
     
  5. beach9618

    beach9618 Member

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    Thanks again for the reply. I know there are alot of differences between 60-66 and 67-72 trucks just as there are between 73-78's.
    My crossmember has two holes drilled in it. One for the forward and one for rear mounting option. The V-8 mounts I bought will only fit in the front mounting position so that's where I mounted it today. Everything like the shift linkage, accelerator cable, etc. line up much better and I like the distance beteween the HEI and the firewall (about 3" now instead of 1/2")in the forward position. The only problem I have now is the fact that the fan sits way inside the shroud (not good). I also have a long water pump which is probably incorrect for a 1972. Anybody know the difference in length between a short and long water pump?
    Thanks for any ideas.

    Jim

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    Last edited: Jan 25, 2011
  6. dvalentine

    dvalentine Charter Member

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    The short water pump will help a lot. Check to see if there is a fan spacer that you can remove. Consider trimming the fan shroud too. ( that's what I did).

    FYI: There are not as many differences between the 64-66 frames and the 67-72 frames as there are with the later models.

    DVal
     
  7. beach9618

    beach9618 Member

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    I currently have a clutch fan, 4 row radiator and long water pump. I thought about a regular fan & cutting down the shroud but not looking forward to changing the pump since it will mean changing my pulleys.
    Thanks again,
    Jim

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    Last edited: Jan 25, 2011

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