Bought a set of junkyard GT40P heads

Good Morning CCF's,

I believe these heads are off a 1999 Mercury Mountaineer. I picked them up yesterday for $135 out the door. Not sure if I got a decent deal. My plan is to take them to a machine shop and have them rebuilt? I'm a noob when it comes to engine work. I have been reading a bit in the archives but overwhelmed with information around 1.6 roller rockers, pushrod lengths, springs, valves, RR camshafts, less than .500 lift, .210 in .220 out. 110, 112, 115, pulling water into the engine via the exhaust with too much LSA, etc.

Could someone be so kind as to give me an idea of what I should be asking the machine shop to do to them? I'm pulling off the old heads because I have oil leaks from the heads, rocker covers, or both. Any recommendations on gasket kits? Fel-Pro ? Replacing rocker covers with aluminum ones. M-6582-A301R

My short term plan/goal, for now, is to install rebuilt heads, rocker covers, and intake (RPM performer?) with new gaskets to seal up the motor from any leaks.

Background: 83 Ski Nautique with 351W that I picked up a couple of years ago. I've performed all of the routine maintenance and upgrades myself.

1023hrs
New plugs and wires 2019.
Fully rebuilt carb by National Carb 2019.
Impeller 2019
Belts 2019
All hoses 2019
Installed fuel filter 2019
1 wire alternator
New throttle and trans cables 2019
Oil, filter, trans fluid change 2019 & 2020
Converted to Pertronix 1.5 ohm coil and ignitor EI 2020 (Prestolite clip dizzy)
Added springs to timing advance weights (one missing, one fully stretched)
Set timing to 8 degrees BTDC at idle goes a little above 30 advanced Adjusted carb. Idles at 650-700 and 600 in gear.
Pulls 15 inHg of vacuum slight movement of the needle not rock solid.
Boat feels pretty good as is.

Just for reference I swear Clearwater Cylinder charged $350 for GT40p hearts drilled for 351 4 years ago and I kept my core. Seems like too good of a deal to be true. But memory fades as I’m getting old.

Wow nice clean manifold bolts and what a purdy color don't ya think Joe

You may be leaving some performance on the table with that timing.

gun-driver wrote: You may be leaving some performance on the table with that timing.

I only set the timing at idle. Should I be adjusting it at a higher RPM and or closer to 10 at idle? The advance springs I installed are fairly light meaning they're not very stiff. It seems like timing advances fairly quickly. I have other springs but they don't seem to be as easy to install or match up as well as the ones I installed. The ones in there now are definitely better than what I had which equaled none.

Keno, thanks for the gasket kit part no.

Any particular silicone on the china wall? I was planning to get new bolts for the heads, intake, and rocker covers. Put the $ elsewhere?

Regarding intakes, which is the better choice, and will it fit under my engine cover with a stock flame arrestor? I do have the stock PCV spacer under the carb. The Edelbrock Performer 2181 @ 4.120" manifold height or the Performer RPM 7181 @ 4.800" ? Older threads from 2006 & 2007 seem to indicate a lower profile 2" or 3" FA is required for certain aftermarket intakes.

Back to your previous post, most any oil resistant RTV will work on the "china wall" and the bolts can all be reused. The head bolts on a 351 aren't torque to yield.

Some people throw them out and replace them, some use them over and have money for other stuff. Your choice

Did they replace those round plugs in the ends of the heads with brass ones like Gary mentioned?

Marseille wrote: Any particular silicone on the china wall? I was planning to get new bolts for the heads, intake, and rocker covers. Put the $ elsewhere? Regarding intakes, which is the better choice, and will it fit under my engine cover with a stock flame arrestor? I do have the stock PCV spacer under the carb. The Edelbrock Performer 2181 @ 4.120" manifold height or the Performer RPM 7181 @ 4.800" ? Older threads from 2006 & 2007 seem to indicate a lower profile 2" or 3" FA is required for certain aftermarket intakes.

Silicone -- I like Permatex Ultra Black for the China Wall

Head Bolts -- Ask 10 people, get 12 answers. I like to go with new ARP head bolts

Intake Manifold -- I would go with the Edelbrock Performer RPM (7181) if you can fit it. On my 1994, I was able to fit the RPM with a low profile K&N filter/spark arrestor. You could also delete the carb spacer if needed. I removed the spacer with the RPM to make it all fit. If you can't fit the RPM model, the Performer (2181) is a great manifold also. If you do go with the Edelbrock manifold, I found that the Edelbrock gasket 7219 fits better than the 7220, which is mentioned in the installation instructions. (thanks to KENO for this recommendation). Another good choice for intake gasket Fel-Pro a 1262-S3 Intake Manifold Gasket set.

JQ

Those heads look like a good deal.

Here are some pics after the machine shop work.

Shane, late to then party here. Pricing for the work seems reasonable. Also, great show called Engine Masters by Motortrend. Couple weeks ago they did some intake testing on an AFR 185 headed stock stroke 351 Windsor. They ran the regular performer and it made somewhere around 425 hp up around 6000 rpms. They swapped to an RPM and only made another 10 numbers or so at peak.

For that engine and RPM requirement I wouldn't even mess with a performer RPM and open myself to potential clearance issues and monkeying around. We run a standard performer on my brothers 89 SN with the stock spacer and flame arrestor without clearance issues.

Id, go that route. The only oddity we had with his intake is it had an EGR hole cut in the exhaust crossover. Make sure if your intake selection has that you get the block off plate and a proper gasket from Edelbrock.

Some later carburetors have an extra port for the PCV but the normal small block 600 generally does not. Stick with the stock spacer and you won't need to reconfigure anything.

You would likely be ok clearance wise if you set up a wedge like Tim said above. I also do not like putting the PCV on an individual port. Aside from running a cylinder lean potentially you'll run every bit of oil vapor into that cylinder rather than spreading it over several.

We were able to keep the factory throttle cable mount on my brothers boat. It works ok but I may end up swapping out to one of the sandwhich style cable mounts that goes under the carb. Works great on my BFN setup. Straighter shot on the cable and much better adjustment potential. The bracket in the link below comes with two gaskets and a mount that is compatible with the Morse style cables (Just like the one on your transmission cable).

Throttle Cable Bracket

Also, even with the stock spacer we were able to bend the factory fuel line to work perfectly fine. I assume if you use a wedge on the RPM a similar setup could be had by tweaking the stock fuel line.

Guys, I really appreciate all of the feedback. It's extremely helpful and valuable as I navigate through the options. I'll keep updating as I acquire more parts for the head/intake swap. I like the idea of keeping it simple. That KN filter sure is nicer looking than the stock SA.

In other news, I purchased the Acme 540 today. It should arrive by the weekend. Seems like a lot of people around here were really happy with this purchase. Right now she is running 46mph on the GPS.

Haven't decided on a cam. I was thinking about giving Scott? at CR a call for a cam and lifters. Someone last year listed this part number CR112016 @ $285 for the cam and lifters. Not familiar with como cams.

Painted one of the heads 1601 (Old Ford Blue). Did I screw up by not masking off the exhaust gasket location?

Not sure why we are “dreaming” since the HO 351w made 92-02 was rated 285-310hp with 8.6:1 compression and a .445 lift flat tappet cam. P’s flow just as good as the regular GT40’s and offer about a point of compression increase on a stock bottom end. Add a slightly warmer cam (like CR’s own .460 grind) and a decent intake and 325hp is pretty commonplace. That’ll push a 2nd gen SN into the low 50’s or better, and have an early 2001 flirting with the 50mph mark.

You probably talked with Scott at CR. Despite knowing fords pretty well and making some decent cams, some of the “knowledge” regarding ski boats over the years has been... well, slightly off the mark. The above referenced build is well proven and pretty tame compared to what some others here have built. Tried and true and a nice upgrade over 240hp no doubt... but if you want reliable 50+ you will need a bit more power in that hull.

In terms of exhaust manifolds, some pictures were posted of a cross sectioned PCM pyramid and they’re actually a pretty nice flowing design. We’ve seen some pretty good performance out of log manifolds on lighter boats too- so while certainly suboptimal, you can still make them work. I’ve got a 331ci p-head engine at 10.3:1 and a cam not far off what CR offers and it’s running almost 10mph faster than stock.

Meh that’s hardly any warmer than stock. The CR cam is a little better at .460, just tell them you want the most aggressive rh cam they can make. Last
I heard the .460 was it based on the blanks they had. Ideally it’d be closer to the .490-.500 range with p-heads but some 1.7’s would get you pretty close.