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View Full Version : GT-40p Heads on Ebay will they work?


TRISTARX
07-19-2007, 12:59 PM
I am looking to purchase some used heads for my 86 tristar 351. Would these work.

http://cgi.ebay.com/ebaymotors/FORD-5-0-302-GT40p-HEADS_W0QQcmdZViewItemQQcategoryZ33617QQihZ003QQit emZ130135191577QQrdZ1QQsspagenameZWDVW

Thanks in advance.

tommcat
07-19-2007, 01:16 PM
GT40P heads are just 5.0 Explorer heads. they will work well as a direct bolt on for a 5.0 but i am not sure how they work on a 5.8.

they work even better if you put in a nice cam with them.

André
07-19-2007, 01:20 PM
Have you done a search here? Didn't read it all but maybe this thread can help you...
http://www.tmcowners.com/teamtalk/showthread.php?t=10133&highlight=ford+heads

Laurel_Lake_Skier
07-19-2007, 01:32 PM
Yes they will work but the head bolt holes will have to be drilled out to 1/2" to fit your engine. Everything else should be the same although brass freeze plugs are suggested in a marine engine. Not sure how the price of the auction will end up but there are places you can buy rebuilt heads for a little more and have everything right. If you end up needing work done on those, they will end up costing quite a bit more. Give a call to Clearwater Cylinder Heads @1-800-572-1963 ......they will do the redrilling and can also install brass freeze plugs before sending the set off to you. I spoke to them a few months back and they are good to deal with.

André
07-19-2007, 02:31 PM
I think i remember the name "Summit racing" as a seller for those heads...

Edit:http://store.summitracing.com/egnsearch.asp?Ntk=KeywordSearch&DDS=1&Ntt=ford+gt+40+heads&searchinresults=false&N=+115

etduc
07-19-2007, 03:07 PM
I am looking to purchase some used heads for my 86 tristar 351. Would these work.

http://cgi.ebay.com/ebaymotors/FORD-5-0-302-GT40p-HEADS_W0QQcmdZViewItemQQcategoryZ33617QQihZ003QQit emZ130135191577QQrdZ1QQsspagenameZWDVW

Thanks in advance.

Yes, they'll work, as mention above. Remanufactured, ready to bolt on, run about $600.00 (steel versions) (Maybe less- call you LOCAL auto parts house) Be sure to ask seller, if these have been checked with proper equipment, or eye-balled. Local machine shop, would charge about $75-100.00 to inspect + parts.

Original head/intake was designed, for low-end and low maintenance. Be sure to replace the intake. But don't go to high. (Clearance issue, plus bottom end performance, will suffer.)

TRBenj
07-19-2007, 03:24 PM
Be careful. You'll likely need a valve job on those heads before installing them- that'll run ~$200. You can find fully a fully reman'd set for $400-600, ready to bolt on. I should know- I bought a set of P's on ebay from this seller and by the time I was done cleaning them up I had way outspent what I planned. They had 1 or 2 bent valves, by the way.

An intake and a cam will help a lot if youre looking to add power. You'll need new valve springs if you want to go near .500 of lift. Id stick with a dual plane intake, but go as tall and aggressive as you can fit under your motorbox- you cant possibly hurt low end. I went with a Weiand stealth and I have a holeshot you wouldnt believe.

tommcat
07-19-2007, 03:51 PM
an Edelbrock Performer intake with a marine cam would be a great combo with those heads.
new carb and an MSD marine ignition would complete the package. great low end power and fuel mileage

TRISTARX
07-19-2007, 05:43 PM
How much HP increase do you think you would get witht hat setup tommcat?

thanks,

TRBenj
07-20-2007, 01:55 PM
How much HP increase do you think you would get witht hat setup tommcat?

thanks,

I think I answered this in my PM to you already, but Ill speculate here as well. The P's should be good for ~45hp over the stock heads. An intake is only going to add a little (~15hp), but a cam that gets everything working together nicely can be worth up to 30hp. I did these upgrades last year and figured I added a solid 80 hp.

Personally, I wouldnt bother with an MSD. They dont make a marine distributor for our Fords, so even if you run a remote box that improves spark, you havent done anything to improve the advance curve. The best ignition upgrade that I have found to be available is the DUI from Performance Distributors. I figure it was worth at least 10hp over the stock distributor + coil.

tommcat
07-20-2007, 02:05 PM
i have installed an MSD marine distributor in a 5.8 before, unless something has changed since last year they are available.

and you can add the marine box at a later point for an even bigger improvement http://www.msdignition.com/mari_1.htm

you should be able to build an easy 300 horse 5.8 with that set up, more importantly though is it's a good low end torque set up

TRBenj
07-20-2007, 03:05 PM
i have installed an MSD marine distributor in a 5.8 before, unless something has changed since last year they are available.

and you can add the marine box at a later point for an even bigger improvement http://www.msdignition.com/mari_1.htm

you should be able to build an easy 300 horse 5.8 with that set up, more importantly though is it's a good low end torque set up

Ive looked, but the only Ford Marine distributor that appears to be available from MSD is for the 351C/460. You *could* run the MSD box with another distributor (even a DUI) but the one person I know who has done so only ran into problems. Not sure if it made any more power.

Im not convinced that a ski boat motor should be built for low end torque. As long as it idles nice, I would rather have midrange power than anything else. Even when stock, i could turn 3000 RPM right out of the hole- who cares about making power below that? I built my motor to have a powerband from 2500-5200 RPM, and I picked up just as much holeshot as I did top end speed (600 RPM). The initial slipping of the prop acts just like a torque converter in a car. Dont be afraid to go more aggressive!

east tx skier
07-20-2007, 03:21 PM
It's been a while since I looked at this, but IIRC, the optimum torque on the Edelbrock performer is 1,800-4,000 rpm give or take. Idle is very good.

TRBenj
07-20-2007, 03:26 PM
It's been a while since I looked at this, but IIRC, the optimum torque on the Edelbrock performer is 1,800-4,000 rpm give or take. Idle is very good.

That may be accurate for optimum torque. The official rating Ive seen is 0-5000 RPM for the Performer. A taller dual plane like the Performer RPM (1500-6500 RPM) or Weiand Stealth (0-6800 RPM) will have an advantage in the midrange without giving up anything on the low end (at least in a ski boat). I say run whatever you can fit under the motorbox.

I have zero idle/driveability issues with my setup.

tommcat
07-20-2007, 03:29 PM
Ive looked, but the only Ford Marine distributor that appears to be available from MSD is for the 351C/460. You *could* run the MSD box with another distributor (even a DUI) but the one person I know who has done so only ran into problems. Not sure if it made any more power.

Im not convinced that a ski boat motor should be built for low end torque. As long as it idles nice, I would rather have midrange power than anything else. Even when stock, i could turn 3000 RPM right out of the hole- who cares about making power below that? I built my motor to have a powerband from 2500-5200 RPM, and I picked up just as much holeshot as I did top end speed (600 RPM). The initial slipping of the prop acts just like a torque converter in a car. Dont be afraid to go more aggressive!
i just called summit and they no longer list it. thats who i got it from last summer.

in comparison to my other engines that IS low end, i guess it's all relative to what you're used to:D