The Rodding Roundtable
Motorhead Message Central => Rodder's Roundtable => Topic started by: butch27 on December 14, 2009, 12:12:10 PM
Got feed up with the poor heads on my '78 Ford 302" and bought a set of 1969 Ford 351" # C90E-d heads. Will they match up with no changes? Thanks
As I remember, no. There are several things that are slightly different. Google 351w head conversion and you will see the specifics.
I believe the head bolts are one.
Summit has some reducer spacers for this. Is this the only problem anyone can think of?
Watch pushrod length.....Watch rocker arms....( Studs vs. bolts---Stamped vs. "Rail type") ....Watch combustion chamber sizes .... Watch the water outlets at the end of the heads on the intake side for possible differance....
This used to be a "performance modification" on earlier 302's ..Main thing was 351's had bigger valves ....Something about longer valves stems also.....
The Biggie .......Those '69 heads have SOFT exhaust seats ....( Ask me how I know ... :oops: )
Bob.............. :wink:
Longer valve stems? I'll knock a ole in a piston! Should have gone Chevy.
"ole"? That must be my English accent.LOL
must use 351 head gasket.something about coolant passages as I recall. Also they have larger head bolt holes than 302 but you can get or make a shouldered washer to fix that.If you are going to the trouble and expense of rebuilding them why not go with aftermarket heads? C9OE and D0OE are the best original castings to use .The rest will lose you too much compression ratio . These heads had a 1.54 intake as opposed to the 1.45 on the 302 ,also a larger intake port. The aftermarket stuff have much better flow and smaller chambers .
I might be interested in the 78 heads since they have the largest combustion chambers,I got a 1970 2 bbl 302 that our modern regular grade of gas is just not enough and its in a daily driver and want to run regular plus I need hardened seats. I guess I could run midrange but I wanted to just run regular and when I was looking for a motor I really wanted a mid 70s motor but I could not pass up a low mile 70 302,I got to pull one head due to a noisey guide so I am thinking about the 78 to 80 something heads that have the largest chambers.
There's a book out by David Vizard with HP books on "how to rebuild your small block ford" 8) He really goes into the "details" of Ford engines and the peculiarities of them. :roll: Like they made 8 different lengths of push rods depending on rocker arm style. :shock: I hope this information might help abit. I know they don't cross breed well. :?
Junkyardjeff:
The '69 Torino heads wouldn't fit bolts were different and some other things so I'm just going to use what I have . Anyone have any ideas on how to improve them a little and to check for bent valves and weak springs?
YES, YES, YES!!!
They will fit!!! Most of the minor mods are shown above
1 You need new head bolts (or studs) with the spacers (1/2 to 7/16 inch)
2 You need the 351 intake gasket with the "L" shaped coolant holes though the Fel Pros cover both 302 and 351 with an insert in the coolant hole which I use
3 You should modify the pressed in rocker studs to 3/8" screw in type - super easy job, Pull the studs, then run a 7/16 taper then bottoming tap s-l-o-w-l-y. BBC studs fit then roller rockers are nice
4 Push rods "should" be the same, but they need checking, JIC
5 You need a set of new head gaskets - they are the same, 302/351.
6. You should make sure there isn't an EGR hump in the exhaust port. If so, a few hours with a die grinder fixes that (just leave the 1/4" hole and forget)
As far as soft valve seats, I personally never had a problem, but possibly a daily driver - or one running a computer controlled FI that tends to be leaner therefore hotter burning. With a carb, probably never have a problem. The valves, much bigger @1.84/1.54 (originals 1.78/1.45), the comb chamber, 60.4cc vs the original 69cc.
This is a mod that really helps a 302/5.0
Of course, if you can find a 5.0 Explorer with GT40P heads, your work is already done, but then there will be other, but minor problems