351w heads on 302

[fnoble 0]

In addition to spacers for the 716 studs V 1/2 inch holes what's involved in putting a 351 Windsor head on a 69 302 block?

 

[jholmes217 65]

You want the 1969 or 1970 (maybe later 1970s heads also) heads with the larger valves.  Later 351W heads are the same as 302 heads.  You will also want to use the Felpro #1250 intake manifold gasket as the coolant passage on the heads and intake manifold are different, but this gasket will work.  Racers used to port the heads and use bigger valves in these heads before aluminum heads became available.  Last time I used these heads (1970 heads) they had 1.94 intake and 1.60 exhaust valves.  Many would also "shave" them to bring compression up.

[1969_Mach1 333]

jholmes217 is right.  You want the 1969 or 1970 351W cylinder heads.  They have larger valves, larger ports, and smaller combustion chambers than later year 351W cylinder heads.  Since you need to have hard exhaust seats installed, it's worth a little extra to install 1.94" intake and 1.60" exhaust valves.  Some squeeze a 2.02" intake valve in them, but they get too close to the exhaust valves.

The exhaust ports need the most port work. There are humps in the roof of the exhaust ports that should be removed.  These humps were later used for smog port passages.  If installed on a 302, you can leave the intake ports alone.

The Felpro performance 1250 intake gaskets work fine.  I have had better luck with Edelbrock's intake gaskets.  They are identical in shape, just a different material better suited for long term street use.  The Felpro performance intake  gaskets tend to wick water at the coolant passages over time.  When I first had that problem, Felpro's tech support told me their performance intake gaskets are intended more for short term use on race motors that are disassembled often, every month or so.  That is one reason why they are Teflon coated.

[barnett468 418]

Why do you want to do that?

1. you do not "need" hard seats installed.

2. you likely need different push rods.

3. you should drill the steam holes in the windsor heads.

4. fel pro laminated gaskets are far better than their non laminated ones.

 

 

 

[1969_Mach1 333]

If you plan on using the car much and run unleaded gasoline you will need hard exhaust seats installed.  Without that, eventually the exhaust valves will destroy the exhaust seats and sink into the cylinder head.  I've seen it happen.

[barnett468 418]

again, you do not "need" hard seats, although they will last nearly forever. i have had, and also built, many engines that did not have hard seats and have gotten over 100,000 miles on some using unleaded gas and the seats were still in decent shape. isolated cases of premature seat wear without any other info is not sufficient grounds to emphatically claim that unleaded fuel will quickly kill old school heads that don't have hard seats, and it can cause some people to needlessly spend a boat load of money on something they may not "need".

 

 

[Rsanter 152]

I am in a different camp, I would rather port and install the larger valves in the 302 heads. Even better I like to run the earlier heads with the smaller combustion chambers. 

You can open up the area around the valves with a fly cutter also if you wanted to

[ray1970 88]

As with Barnett I get tired of hearing about harden seat replacement on motors that most likely will never to see

20000 more miles in there life.....Not really needed....its a feel good thing....If the seats are trash go with it....  I could be wrong..

[barnett468 418]

25 minutes ago, ray1970 said:

As with Barnett I get tired of hearing about harden seat replacement on motors that most likely will never to see

20000 more miles in there life.....Not really needed....its a feel good thing....If the seats are trash go with it....  I could be wrong..

you are not wrong.

installing seats is a big "upsell" with big profit for head rebuilders, so most of them tell customers they need hardened seats and try to scare them into buying them. i know this for a fact because i ran the cylinder head department for a big machine shop for a while but i never upsold anyone but i did install over 1,000 seats in heads that the seats were trashed in.

[Vicfreg 771]

I installed GT40 heads from a Ford Lightning on my Roller Cam 5.0, used the different bolts and the correct gasket. No issues.  

[1969_Mach1 333]

The GT40 are nice factory cylinder heads.  Just, very hard to find.  There are a lot of the GT40 P-heads used on Ford Explorers.  But the spark plugs on the P-heads have a different angle and cause exhaust manifold or header fitment issues. 

[Vicfreg 771]

Right.  The GT40 heads have 3 "bars" cast into the front of the cylinder head.  The GT40P have 4 bars.

Also, the Ford Lightning heads are O-Ringed, and require special head gaskets, as the Lightnings that used the 5.7 L were supercharged.