401 non-magnum

[Hobbs]

Hi, new guy; great forum! I have a 1966 1500 with a 351E. From reading the main site this would appear to basically be an M engine. I have a chance to buy a complete 401 non-M. As it was in a fire truck it has low miles and a bunch of accessories and pulleys, which is good as I want AC and PS. My question is if I put the 351E heads on the 401 won’t I basically have a 401M?
Thanks!

[WE7X]

If you change to Magnum heads, you will also need the exhaust manifolds, because the exhaust ports are different. IIRC
Rod J
Issaquah, WA

[sclor]

Hobbs:
I believe the answer to all of the above is "yes". Better make sure you can get Magnum gaskets for the swap. Magnum intake and exhaust gaskets are getting hard to find. Non Magnum are pretty readily available.
Regards
Steve
New Orleans

[63gmc4x4]

im gonna be making my intake and exhaust gaskets for my 351E , it the head gaskets will be the hard part to find or make

[sclor]

Hobbs:
I always figured if I needed head gaskets for my 351e, I would start with copper head gasket for 305 which is pretty readily available, then enlarge cylinder opening slightly for the difference in bore size. Hope that helps.
Regards
Steve

[63gmc4x4]

Hobbs:
I believe the answer to all of the above is "yes". Better make sure you can get Magnum gaskets for the swap. Magnum intake and exhaust gaskets are getting hard to find. Non Magnum are pretty readily available.
Regards
Steve
New Orleans

impossible to find! i even called fel pro , they gave me the finger! hahah im making my own

[TJ's GMC]

Heads, exhaust and intake manifolds, bout it. Hey why not mill the intake and swap on a 4 barrel while you are at it? Food for thought.

[Hobbs]

Thanks for all the replies! I wanted to respond sooner but I had problems with my login. Guess it’s time to learn how to modify a head gasket...