Thread: 478 to SM420
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Old March 9th, 2017, 03:24 PM
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Default Re: 478 to SM420

Quote:
Originally Posted by arepoff View Post
I know, this has been gone over before but I can't find the answers I am looking for in the archives. I am thinking about replacing my 305E with a 478M in my 65 K1000.

1) To adapt the sm420 to the 478 I need either the 379 flywheel (rare) or have a custom flywheel made.

2) Does the sm420 bell housing bolt directly to the 478 SAE housing?

3) If the same exterior accessories and single row timing chain is used on the 478 it should weigh about the same as the 305.

Please let me know if I am correct. My grandfather bought this new and I inherited the truck, now that I am getting ready to restore it I would like to have more power but keep the V6 engine. I also plan to install an HEI distributor and a FiTech fuel injection once I modify the M intake manifold.

Thank you in advance for your advice.

Alexi
I haven't done a ton of research yet so someone correct me if I am wrong:

I believe you will need the smaller truck style bell housing as the big truck housings are much bigger and so would the trans bolt pattern for the big 5 speeds and other transmissions that came in them.

Just taking off most of the big accessories will make the 478 much lighter.

The HEI and fitech fuel injection system will be sweet! Be sure to post up power and fuel mileage results if possible!
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