Motor mounts..Bolt or Weld - The 1947 - Present Chevrolet & GMC Truck Message Board Network

cottonme173 · 11-01-2017, 12:38 PM

So, I am putting a 454 in a '78 that started life as a diesel so, the motor mount holes do not line up. First thought was to set the motor mark holes and rill the now ones..easy peasy... I started thinking though...would this weaken the frame just that much more putting more holes in it? So, the other option is to weld them in and eliminate that issue (if it is one).

What are your thoughts given this situation? I am a good welder and have one, so that's not an issue. I will never put anything but a BB or SB in the truck so I wont need to move them.

Thoughts?

74CustomK20 · 11-01-2017, 12:42 PM

I thought all the trucks used the same mount holes n just moved transmission cross member?

cottonme173 · 11-01-2017, 01:44 PM

Quote:

Originally Posted by 74CustomK20

I thought all the trucks used the same mount holes n just moved transmission cross member?

The 454 I have came out of a 1977 c20. I kept the mounts and the truck i'm putting it into is a 1978 c10 that had the 6.2 Diesel in it. I wish you were correct, but my holes don't line up.

DieselSJ · 11-01-2017, 04:43 PM

Quote:

Originally Posted by cottonme173

The 454 I have came out of a 1977 c20. I kept the mounts and the truck i'm putting it into is a 1978 c10 that had the 6.2 Diesel in it. I wish you were correct, but my holes don't line up.

They should. The SBC, BBC and 6.2/6.5 all share the exact same mounting dimensions.

**kwmech** · 11-01-2017, 05:04 PM

1978 would have the infamous 5.7 olds diesel. The 6.2 did not come out until '81-82. It it truly had the 6.2 it was converted and if the mounts don't line up with that being said you have other issues

cottonme173 · 11-01-2017, 05:15 PM

Quote:

Originally Posted by kwmech

1978 would have the infamous 5.7 olds diesel. The 6.2 did not come out until '81-82. It it truly had the 6.2 it was converted and if the mounts don't line up with that being said you have other issues

Well that explains a lot! When I bought the truck there was no motor in it. It did come with 2 diesel motors a 6.2 and a 5.7! The PO told me the 6.2 was in it, but as it turns out from other issues I found, he was probably mistaken. So the 5.7 did have different alignment holes for the motor mount and that's why mine wont line up?

11-01-2017, 12:38 PM	#1
cottonme173 Registered User Join Date: Nov 2013 Location: Sherwod, Or Posts: 77	Motor mounts..Bolt or Weld So, I am putting a 454 in a '78 that started life as a diesel so, the motor mount holes do not line up. First thought was to set the motor mark holes and rill the now ones..easy peasy... I started thinking though...would this weaken the frame just that much more putting more holes in it? So, the other option is to weld them in and eliminate that issue (if it is one). What are your thoughts given this situation? I am a good welder and have one, so that's not an issue. I will never put anything but a BB or SB in the truck so I wont need to move them. Thoughts?

11-01-2017, 12:42 PM	#2
74CustomK20 Registered User Join Date: Oct 2014 Location: Tell City, IN Posts: 637	Re: Motor mounts..Bolt or Weld I thought all the trucks used the same mount holes n just moved transmission cross member? __________________ Big Nate Carp. Local 224. Buy made in the USA! 03 F350 6.0 Daily Race Truck. 79 C70 366 Project Dump.

11-01-2017, 05:04 PM	#5
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,637	Re: Motor mounts..Bolt or Weld 1978 would have the infamous 5.7 olds diesel. The 6.2 did not come out until '81-82. It it truly had the 6.2 it was converted and if the mounts don't line up with that being said you have other issues



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