GT40P Head Identification

I had a 91 5.0 sedan,a Ford program car,one of the best cars I've ever had.Bought it because of the boat,just had to have two Mustangs. I think JoeinNY runs aluminum heads, most tho just run P's. I have a set of these, Tri State some have bought from here,Clearwater. We here have found out it's cheaper and usually better to buy from these guy's as by the time you get a set of used heads,get them rebuilt, your over Clearwater or Tristates prices. You on the other hand might have an "in"

Those Explorer heads are the ones Rich. The diffrence between auto and marine are the brass freeze plugs. To mount them on a 351 you need to open the head bolt holes to 1/2"

Dave if you are keeping the stock cam you can also check the gt40p heads from clearwater heads..they are also fully reaconditioned but with the stock spring, they cost around $420 agains the $600 they ask for the tristate..
If you decide to change the cam then yes get the tristate ones as they have the hardened spring to handle more valve lift...

Dave, I don't think you'll be impressed by putting a reconditioned stock prop on there. It may run smoother but I don't think you'll see much change in performance. You need to test with an Acme or OJ to find out whats going to work for you. The new CNC's are drastically better than what came on your boat.

Alan....Yes, my prop has seen better days. I chewed it up pretty good one evening on the Fox River being the good samaritan towing a guy who ran out of gas and we got into to some shallow water. But, believe it or not, while it looks rough, I only lost 1 mph. However, I do have a new/rebuilt stock prop I haven't put on yet. Todd W. told me at Clinton he would try new points as well. So, I thought I would do some testing yet this season to try my other good prop, and a tune up kit to see what that does.

By the way Alan...I appreciate your advice on the loading racks. I got mine fabricated and on the boat last weekend. They work great, and it was an easy job! Should have done that a long time ago.   

Gary....I appreciate your offer. I hear what you are saying about the used heads vs. Tri-State. Risky, I know. I just need to be careful about how much $$$ I put into the boat. I will probably never get it back out. But, I guess I can always take the heads off and transfer them to another boat (would like to get another Southwind Bow Rider). However, it wouldn't hurt to take a look at the heads you have. Lets talk offline to work something out. Maybe I will put the boat on the river and head down to Algonquin. Still itching to get it out and do some boating. Are you on the river?

David DON'T. Friends don't let friends buy used heads on ebay! You just can't look at them and see what your bidding on, when it comes to used ones. I bought some last year and one is junk,it has a hole behind an intake valve to the water jacket . If it would help, your welcome to have them if you want, shipping from Algonquin to Cary would be no problem

Guys....slight threadjack here, but, pertains to GT40P heads for my boat.

'76 Southwind. Freshened up 351 w/ new rings, bearings, and new stock cam. All pistons pushing 125-140 psi compression currently. A real dog out of the hole pulling skiers though.

Alan put the bug in my ear at the Clinton reunion about GT40P's, and I have been keeping my eye on ebay for a good used set.    

Questions:

- Will the GT40P heads alone wake up the power, or do I need a Performer intake as well. I plan to stay with the stock cam.

- What is the best pop for the money for improved hole shot and more power on top end for increased speed while towing? Can't seem to get it above 30-31 MPH while towing a skier.

- Also thinking about an Acme prop vs. current stock 13 x 13.

Just curious as to what has provided the biggest performance boost for others.

they would ship only ups/fedex or so...thats why its so high. you need to send it to someone in the US that will send it to you on a regular mail (if possible)...

lOoks like a single plane Victor jr to me, which is what is on my 408. I think itnwould be a great manifold with the right cam. However the motor box or at least flame arrestor will need a cut or two. And that distributor won't fit, most won't without a grinder but an hei style is a definite no go.

I picked up those GT40p heads a couple of weeks back. Have been looking for a inlet manifold before I do the head swap. This manifold turned up on Ebay.

Intake Edelbrook

It looks to be a single plane highrise. Not a air gap more like a Victor Jnr. Not sure if it will be any good for a ski boat. I know Joe put a single plane on his stroker but it had bags of torque anyway.
What do you think it only has 40mins to go so I need to act fast. We just dont see many 351W manifolds in Aus plenty of 302W.

Also would it clear the engine cover ??

I posted somewhere else that a big ford guy told me that the older Aussie ford built heads were better than the US built heads...why, I dont know, emissions? has anyone else heard this?

Sebastian,how did you get the brass freeze plugs? When I ordered mine they said I could not get them. When the warrenty goes off I'll just replace them.

as for the cast on the heads, mine do have the gt40p cast on them...and the 4 bars also

Unless youve got some weight in the boat (in the rear) then it looks like it rides fairly bow-high to me. Mine runs pretty flat at all speeds.

Seb, each hull pops out of the mold a bit differently. There were probably multiple molds as well- so while we do have the same hull, no 2 are exactly the same.

If it came out of the mold with less hook, it will run a little more bow high, which means there is less wetted surface (drag) and the boat will run faster. You will notice that the spray breaks further back towards the pylon or motorbox on a bow-high hull.

If it came out of the mold with less hook, it will run nose low. This means more wetted surface (and more drag) and the boat runs slower. My '90 is the worst Ive seen in this regard, and the spray breaks at the forward part of the windshield- I can see it when I drive. Keith's '94 and my uncle's '90 run noticeably more bow high. My '90 was a real underperformer when I bought it- it turned a cool 41mph @ 4200 RPM's until I threw some power at it. Now I get a consistent 46, and will hit close to 48 with ideal conditions, a full tank of gas, and 4 bodies in the back seat. Its a little pathetic! Holeshot is pretty respectable though.