Looks like you are building a fun hot rod. Looking forward to seeing the completed project.

Ok so plumbing, trying to get parts ordered and organized. So I'll run the drive p/u and an adjustable thru hull p/u to the sea strainer. Then one 1.25" hose out of strainer to Hardin two stage water pump common input. Should be good there. Things I'm not sure about

If I put a pressure relief valve on my strainer (it has a port for it) will it work the same there as if I put one after the water pump?

Can I plumb water pressure relief to same discharge as my bilge discharge with the help of check valves? If I could do this then I could use one three port discharge fitting. 2 ports for each of the intercooler discharge lines, and the third for the bilge/water pressure relief...?

Black cloth braided hose for the intercooler lines or the stainless braided? Seems a lot of the guys use the black cloth now.

Good luck with your project, dont consider wasting your time with a SC lower if you want trouble free boating, any kind of decent hp and prop they fall apart quickly in a vhull, i lost count of how many bravo lower gears i chewed up in my old baja. What was your old power you had that got you to 70mph, havent seen many 25 outlaws or 272s w black motors that could break 65 or 66 mph at 750 feet elevation stock, Smitty

70 mph with original setup - stock 496HO, bblades labbed 25 mirage plus, propshaft 6.875 below bottom, 15" x dimension. 67mph with stock 23 mirage plus. I see a lot of outlaws running 4 blades with stock setup but that's not necessary if you ask me with the prop plenty deep in the water, using too much power to spin an extra blade. The mirage pluses had awesome trim reaction.

Saw 69 mph briefly, 68 more consistent, on my gps last season after extension box and higher X. That was with a stock 26 bravo 1 that had pretty poor bow lift. I think if I would've had that 26 labbed I would've been back to 70 or just over.

So I did not gain any speed with the extension box but the box should start show benefits once speed starts to increase substantially. Shooting for low 90s

For the plumbing you should be fine to use the same port with the check valves unless 2 things try to pump water through it at the same time. If you have that much pressure that's it's always running the relief and one of the others need to exit water it won't work. It can only flow so much fluid through it. Your best just to put another fitting through the boat.

Great thread, I like it. I'm interested to see your results. I pulled just over 8mph out of my 25 with a neutral box, 525sc, k planes and stock length lower with a 28p. Scalded Dawg's 25 runs mid 80's with a 454mag bored and stroked to a 496 with a top mount whipple, dry exhaust, neutral box, imco scx, -2 lower and the engine was raised 3". I also considered where and how to put my k planes. Stephen (wildcard) had 24" Eddie Marine tabs walked way in on the vee but not straight. I ended up using the exact measurements off of a friends 90+mph 25 AT Tantrum. Best of luck with your build, it's really sweet!

Thats pretty damn good starting point, will be interesting how much gains you get from the hp increase. My 272 ran 78ish w 650-675 hp, ran 84 ish with 750hp, ran 92 ish with 950 low on gas and 2 passengers, ran 95/96 with 1050 hp, ran 99ish with a little over 1100 hp. My stellings box hurt top speed no matter what props i tried plus made boat porpoise. My imco-2 couldnt carry bow and would blow out at mid 90's, lost control of boat last time i had it on, bow hooked and slmost got ejected, took all that stuff off and sold it. Btw, my prop cl was 7.5" below pad, any higher and boat hated it for what ever readon. My theory is above 85 boat was waay out of water so even if cl was 7.5 it wasnt really at speed, Smitty

Thanks guys. Jersey outlaw and Smitty both of your setups are impressive and offer a lot to be learned from.

Being that the 272 and 25 OL were so much alike rub rail down it surprised me when I read how much your boat hated the ext box. I assume you checked for hook or rocker. I'm trying not to get too optimistic about top speeds, won't be able to do that much anyways, but if Stephen was able to obtain 81 with a 525 (540ish hp?) and 84.8 with a 600 (580-590 hp?) I should be able to see 90s as long as our bottoms are close to the same. If this motor were going into his hull he would be around 95 going off of the previous motors. I think the key really is to get as much out of the water as possible to reduce drag while maintaining correct ride attitude and bow lift. We'll see if I can get a -2 and a good 5 blade to work...

Thats where a scx even though it may slow you down will be a better option than s sc, i bolted a 28 pitch 5 blade maximus on and almost instantly sheared off a max machine worx billet torsional prop shaft. That stephen guy from germany got amazing speeds out of his outlaw with very little hp, i started modding my 272 back in 2001and tried everything to make it go faster for 14 years and only thing that ever worked was more hp, boat had very little hook in it, i heard having trandom edge ground real square is worth something but after bolting on stellings box and having to drag tabs hard to keep it from porpoising i never rolled the dice and did it . When my 540 was making 1050/1100 hp blown it made 650 with blower belt off, boat ran 76 on a good day and 74/75 on a typical day tutning a labbed 26 5600. Ive talked to 20+people thru years with modded 25's and 272's, very few of them broke 80 mph gps with even blown 502s. I tslked to a guy from wisconson who worked at cmi who claimed he had a roots blown 272 with 850hp that ran 88 then ran 92 after in stalling a ext box. My boat ran mid 92's on a good day at that time with 950hp, installed stellings box and couldnt get it past 89 and change, pissed with that setup a whole summer, tore it off and went back to what i had and ran mid 92s again following weekend. Worst thing was it had a annoying porpoise at higher speeds w box, just keep in mind when chasing speed not every mod gives you speed gains, it can be slot of work and frustrating. Cant hardly wait to see how it works for you, I'd love to hear you get well into the 80s, Smitty