Carb Suggestion

[Quigley]

Working on a 401 Magnum and am going to put a 4 barrel carb on it. I am thinking a 650 Edelbrock and was wondering what some other thoughts might be? Also I am looking for a set of pristine magnum exhaust manifolds, I have a set, that have a couple of gouges in them. Thanks in advance, Dave

[bigblockv6]

A 650 cfm sounds good but I would consider a cam upgrade to complement it. I do have performance specs for a regrind of your stock cam, here they are as well as anyone else that's interested

[TJ's GMC]

650 would be a great choice....heck I used to have a 600 on my 305. It likes the 500 eddy much better though.

[bigblockv6]

I'm pretty sure this is the regrind, I have given the specs to several members and they are using this cam grind in their 401M engines. One member didn't want to go with this grind and chose a milder grind. If you have doubts then contact someone that regrinds cams and ask them for their opinion.

[bigblockv6]

Originally Posted by bigblockv6

A 650 cfm sounds good but I would consider a cam upgrade to complement it. I do have performance specs for a regrind of your stock cam, here they are as well as anyone else that's interested

The valve springs used with this cam are longer than stock due to more lift in the cam. My machinist used Competition Cams #972-16 valve springs that actually fit Ford 390 applications.

[Firepower]

.425 lift seems what the factory manual calls, and open/close timing is generous, but tough to say what lash does to those numbers.

[Robert B.]

Quick question: is it necessary to replace the entire carburetor (Stromberg on my ‘63 3/4t, 305E V6) if the screw hole which retains the choke arm is stripped or incapable of holding a screw?? I believe it’s been rebuilt once.

Thank you,

Robert

[TJ's GMC]

Originally Posted by Robert B.

Quick question: is it necessary to replace the entire carburetor (Stromberg on my ‘63 3/4t, 305E V6) if the screw hole which retains the choke arm is stripped or incapable of holding a screw?? I believe it’s been rebuilt once.

Thank you,

Robert

You could try a helicoil, but with how popular those carbs are I'd say find another.

[James]

Originally Posted by Robert B.

Quick question: is it necessary to replace the entire carburetor (Stromberg on my ‘63 3/4t, 305E V6) if the screw hole which retains the choke arm is stripped or incapable of holding a screw?? I believe it’s been rebuilt once.

Thank you,

Robert

I would also helicoil it. I have done this many time with no problems. If you need to buy a kit be sure to also buy the correct drill bit that the kit call for.