Vintage Mustang Forums banner

1 - 4 of 4 Posts

·
Registered
Joined
·
173 Posts
Discussion Starter #1
I’m trying to figure out what carb this is and if it’s worth rebuilding or moving on to something else. I know it’s a 4v and is probably part of the low emissions group as the the car once had the thermactor pump and equipment and still has the IMC distributor.
 

Attachments

·
Registered
Joined
·
5,046 Posts
That is a 4300 and is a replacement part from Ford as denoted by the 'P' character. 1975, so right as the 4350 came out. Major visual difference is the 4350 has a big square port behind the choke plate. What is this carb on? The 4300 is known to be problematic as it was an emissions carb. If you can get a decent 4100 core and rebuild it yourself, that would be way better. The Edelbrocks are fairly worry free and perform well. Depends on what you are going for here. For a worry free DD, I'd have to go with the Eddy.
 

·
Registered
Joined
·
173 Posts
Discussion Starter #3
Thanks for the insight. It's on a '68 J-code 302 and starting to run rough and leak. If it turned out to be something not worth rebuilding, which it sounds that way, I was thinking of replacing it with a Summit carb. This is for a weekend cruiser and every now and then road trip car that is pretty much stock. Do you think a 500CFM is good or is it better off with a 600? Thanks!
 

·
Registered
Joined
·
5,046 Posts
Historically for the 289s, the stock units were 480cfm (4100 with 1.08 venturi), but some early 289's got the 600cfm (4100 with 1.14 venturi) units and they were not Hipos. I have a 1406 (600cfm) on a 302 and it runs great. Not even a hint of running rich. Your J code 302 has small combustion chambers so it should do well up to 600cfm. The Summit carb is the happy marriage of the 4100 with the versatility of the Holley design without the leaking bowl issue. I have not run one, but someone here should be able to chime in on that.
 
1 - 4 of 4 Posts
Top