[Guest]

Could use some help. I have a 66 Mustang with a 289, used to be a 2 barrel, but someone somewhere changed the manifold and carb to a 4 barrel. I am positive the heads are orig. REbuilding the motor and the guy doing the work needs me to id the heads, or at least need to figure out if the heads are diff for a 4 barrel oppsed to a 2 barrel ....thanks

 

[racer_x_76]

From what I've seen of both 2bbl and 4bbl there isn't much in the way of differences. As far as I know they use the same valve sizes, same spring diameters. Combustion chamber size is the only difference I can think of. Unless you have a set of "K" code heads they're all pretty much the same.

Every day is a holiday if you love your job.

Current projects: 65 Fastback, 68 Coupe Oval Track Racer, 64 Galaxie 500 XL, 54 F-100 Pickup

 

[johnpro]

On the 289/302 they're the same (except the K code heads). There's a BIG difference on the Cleveland heads.

If you always do what you've always done,
You'll always get what you've always got
http://www.classic-mustang.net/johnpro

 

[Guest]

The 2bbl heads are the same as the 4bbl head (not counting the solid lifter H.P. head).
The different (2bbl/4bbl) compression ratio's and subsequent need for higher octane gas was acomplished by different pistons.
jimbo

M.C.A.# 50000
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[camachinist]

As far as rebuilding goes, 289 heads are the same, even the K-coders...I'm talking about parts and procedures.

They take 1.78 intakes, 1.45 exhausts, use a standard 11/32" guide or guide sleeve and a standard Ford or Chevy screw-in stud (if so equipped). I don't remember spring OD's ( I run racing springs) but they're dumb stuff standard too for all those years...

Find another machinist? *G*

Pat
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