Making 1986 PCM 351 into a ProBoss engine and PCM transmission question

[singing skiier]

Anybody know if a 1986 PCM 351, 260 hp block would mate up with GT40 heads, EFI intake manifold and EFI equipment? Would it give the performance of a ProBoss?
Also anyone had any experience with rebuilding a PCM-40 Vee Drive?
Thanks,
Singingskier

[Mamigacz]

I've done the gt40P upgrade on my boat. If you get the heads from a mustang, Explorer or Mountainer, they will be set up for a 5.0L engine. I got mine from a Ford explorer. The mounting holes that secure the heads to the block, need to be opened up to work on a 5.8L. I spent about an hour on the drill press reworking mine.

It's possible that if you buy the GT40P heads from skidim, they might not need the mounting hole rework.

FYI
I think mustang's had GT40 heads
Explorer's and Mountaineers had GT40P heads

Do you have a doner efi set-up from another marine engine?
Are you thinking about doing a cam upgrade too?

[singing skiier]

I was thinking of purchasing a PCM 1986 PLD Model (260 hp) with 6 original hours on it to replace GT 40 (PLP EFI Model) on a boat I currently own. The prior owner allowed it to incur freeze damage to block and heads. However; I got in touch with Allen at PCM today (and my Nautique sales friend finally talked to his mechanic, who concurred with Allen)-that to use my EFI from the broken engine, I need another PLP Model engine-doesn't have to be a EFI, just a PLP. The PLP has different pistons, cam and of course the GT 40 heads. The EFI makes it the GT 40 engine. Which Model are you using with the GT 40 heads, and what fuel system? Did you change pistons and cam? I've found GT40 heads used for $300 a pair, but finding the block is the problem. According to Allen, changing the pistons and cam would have been cost prohibitive on the 86 model.
Thanks,
Singingskier

[Mamigacz]

I don't have a nautique (Centurion). My engine is:

-Standard rotation (LH) PLD (originally 240HP)
-Upgraded with GT40P heads
-Upgraded with a ski boat cam from cam research
-Upgraded with an edelbrock performer RPM intake
-Stock crank and pistons
-Still set-up with a Holley carb

[singing skiier]

What did it do for you over the original motor? HP? Speed? Hole Shot?

[Mamigacz]

I know this might sound long winded, but I bought the boat as a project. The floor and upholstery had to be torn out. The orginal motor had 1200 hours on it. I never got to drive the boat until a year after I bought it. During the restoration, I put the gt40P heads on it. The first time I drove it, it had the upgraded GT40P heads on it already. I don't know how it felt with the original heads so I never had a good comparison. Three years later, I decided to rebuild the motor.

-Oil pressure was low
-1300 hours
-After oil changes, the oil would get noticable dirty after two ski trips
-My assumption was the cam was worn

During the rebuild I:

-Had it bored .040" over
-Cast iron intake was replaced with the Performer RPM
-Stock cam was replaced with the high performance cam
-Valve springs were upgraded

After this change there was a noticable increase in power. The Max RPM increased an additional 400RPM which did increase the overall speed (approximately 3-4 MPH). Hole shot did feel more aggressive. My assumption was the Cam had the biggest effect on the power increase after all these changes. Its hard to say how much each change had because I did too many things at once.

This is an opinion, but I think the engine has around 300HP. Its never been dynoed, so I don't know for sure what the horsepower increase is from a stock 240hp motor.

[TX-Foilhead]

I think the general consensus is that cam, GT40p's and a dual plane intake upgrade comes to about 325hp on the reverse rotation carbed motors where the cam is limited to a little less than .500 lift. With a regular rotation motor you could get a bigger cam and better heads, but since you can't change the fuel injection programs on a GT40 I don't know how far you could go before that becomes the limiting factor.