I will check on it. I don't use many Speed Pro pistons, so I don't know the answer off the top of my head.
Meantime, look at the piston at the edges of the wrist pin hole. Are there grooves in the outer edge of the pin boss that looks like it would take a clip or spiral lock?

Just for info, Scat offers both floating and pressed pin models

What size engine are you building there ? I noticed those are 427 pistons. Just wondering if you had the right pistons beings you don't see to many 427's around anymore. Those are for use with a 3.75" stroke crank. If you sell those pistons and rods I would sell the crank also and get a 454 crank (4" stroke) or a 4.25" stroke crank which would give you 482 cu.in.'s. Same block and bore used for all, different pistons though. If the block is used you really should go .030" over.
No replacement for displacement!!


http://www.jegs.com/i/Sealed+Power/844/L2268F/10002/-1#

[QUOTE=picklenjim;3038657]What size engine are you building there ? I noticed those are 427 pistons. Just wondering if you had the right pistons beings you don't see to many 427's around anymore. Those are for use with a 3.75" stroke crank. If you sell those pistons and rods I would sell the crank also and get a 454 crank (4" stroke) or a 4.25" stroke crank which would give you 482 cu.in.'s. Same block and bore used for all, different pistons though. If the block is used you really should go .030" over.
No replacement for displacement!!QUOTE]

They're the right pistons! I'm building a 439 the block is .060 over. I've had a fair amount of people say what you're saying with the whole "no replacement for displacement thing". Yes there is truth to it but I really love the sound of a high reving BBC. Yes I could go bigger but there isn't any need. GM has the zz 427/480 that puts out 480 hp 490 tq and the power is in all the right places. So if a factory motor with a warranty can do that what can a built 439 do? Bob Mandara is doing the cam and I'm going with a set of afr heads from him. This engine is going to scream. A formula 242 (26') is only 4150 lbs. A fountain fever which is only a foot longer and a little wider is over 5000 lbs. So for what it is its actually light. Although a fountain has a faster hull. Either way, I'm certainly going against the grain on this, but thats part of the fun. Everyone does 496's.

Eddie- Not sure about the pistons. I'm not around them right now. I'll have to look.

chances are they do. i have a set speed pros (pressed fit) sitting here right now that are for a 4.310 bore / 4" stroke. chances are they have the clip grooves in all there pistons regardless. makes sense. when i first got them i thought they were the wrong ones...

That would be great if that is the case! I agree it would make sense to build them that way. Why have to build and stock two pistons for every application. That would be expensive!

Either way, I'm certainly going against the grain on this, but thats part of the fun. Everyone does 496's.

That's for sure !!!!! Good luck with your project , just remember fun is never cheap. :lolhit:

[QUOTE=
That's for sure !!!!! Good luck with your project , just remember fun is never cheap. :lolhit:[/QUOTE]

LOL- I sure know that, and there are so many ways to build something..... I was originally shooting for 400 hp. Now I'm going for 550 hp. It's a never ending circle. Oh well, gotta love boating!

I'm pretty sure the receiver grooves are in the pistons for the retaining clips/spirolocks. I just didn't want to say for sure since I am not 100%. The pistons really don't care if the rod has a floating pin or not. The interference fit is in the rod, not the piston. Personally, I would use a Scat rod. Make sure you spend the extra few dollars to go with the ARP 2000 bolts. They come standard with the ARP 8640 bolts, but the 2000 bolts are not that much more and are quite a bit stronger. Should be a screamer. Good luck with it.
Eddie

I called Speed Pro today. My pistons are press pin only. So it looks like I'm sticking with I beams.