I'm in the market for some lowering springs.
Seems like the M-5300-B springs from Ford Racing Products would work for me.

Found a set of used springs. Seller claims for them to be B springs but the set of 4 part number is long gone. There are numbers from the front and numbers from the rear.

Can anyone here tell me what these are?

3R335310CA MCH

and on the other pair

3R33551BB MRH

 

These two are the parts number for the front and rear springs; with the last two letters being another way to further identify them.

3R335310CA = 3R33-5310CA (Front 2003 Mach 1 OEM)

3R33551BB = 3R33-3551BB (Rear 2003 Mach 1 OEM)

I do not believe these are the same as the FR B springs.

 

Excellent information Socal
Thanks for the reply.

Where did you get these numbers from?

 

Well, first I recognize certain patterns in FoMoCo part numbers. Second, the topic has come up a few times, but on different forums. I also have some spring charts for some Mustang models.