Excel/barefoot Prop selection after rebuilt engine

Finally (long process with our new son) the rebuilt engine and trans are in the boat. Wanted to check with the experts about a new prop since there are not too many with the 454 chevy (1991 Excel). V-drive is a 1.21. and velvet drive is 1:1

WOT with 2 people and 25 gal gas, and lake elevation at 550" was 4250RPM and GPS 49 MPH, 3500 RPM= 42MPH, 3000= 36.5MPH, 2200= 25 MPH. Newer tachometer and verified with a timing light with RPM also, Added 700lbs ballast and MPH went down to about 47.5 and just a few less rpm (hard to tell).

The prop that came with the boat is an ACME 380 (stamped on prop is 13.5" diameter x 17.5" pitch VR). Looks like some 380's were 17" pitch. I shorten my prop shaft to get more clearance from the rudder.

I spend about 20 days at the lake a year. Almost half at 3600' and the other half around 700' elevation.

My engine builder is not afraid of high RPM for this engine. Compression ratio is just north of 9. Cam was reground (I have numbers available if needed). Running 91 octane gas and timing is set at 34*. Intake manifold is an Edelbrock Performer 2-0.

Last year with old engine, at 3600" lake with about 1250lbs of people and a full tank of gas it barely, I mean barely got on plane. Thats one of the main reasons I'm looking for prop. Looks like this year will be about the same amount of people weight, probably more.

WOT with old engine and new engine is about the same RPM and MPH.

I see ACME 644, ACME 536, OJ 431, Im sure there is others. Is ACME better than OJ? What prop looks like the best. Thanks for the help, including all people in the old topics that I have read.

My friend had the same boat with the same engine and he ran the ACME 328.

Doubt you can really compair but just for info my gt 40 powered vdrive ss is turning a 380 at 4700 and 46 mph

Did not realize there are so many ratios now I wonder what trans mine has---

Dave, I'm not sure you need to sacrifice 4 mph. You're dropping pitch to bring your engine into it's optimum powerband by gaining 400-600 rpm at WOT. I don't see why you won't improve your holeshot and ability to roll over onto plane while keeping close to your current WOT speed.

Yeah not the 380... I'm thinking of the acme that fits a non-short shafted excel. Is that the 328? Whatever it is, it's a pancake and I'd avoid using it on a boat that's been short shafted to allow use of a raked prop.

I thought the heads were oval. My heads looked stock, looked like original paint. I'll have to look at pictures from last year when I had the heads off. I told Jim that I have 2" if clearance from prop to hull and he said he want me to run the largest diameter prop for better weight carrying and holeshot. I know he also compensated for the elevation. He also mentioned the extra cup would do better for me.

Hopefully I don't pass 4800 rpm with the peanut heads so I don't run out of air.

My next lake day will be at 3600 with the new prop. All things being equal, if I tach out at 4800, then move down to 600' elevation, how much of a difference, could anyone guess?

You guys have me worried now. I had 2" clearance between prop and hull. New prop should be 1 5/8" probably closer to 1.75". Jim said that's plenty of room but in your opinion is that bordering in too close (you guys own the boats and see, Jim only gets to hear what's told to him). Should I be looking at the 13.5" props?

Link didn't work but I figured it out. Thanks for the thread, it helped me to see that it will be close when I run on the lower elevation lakes. I'm in a hard crash course on prop engineering. I see that the extra cup will make the prop not be efficient at high speed.
Prop #1 ACME 1846 14 x 14.25 with .150 cup (raise rpm 500-600 rpm)
Prop #2 ACME 536 13.5 x 16 with .105 cup (raise rpm 300-350 rpm)
Prop #3 OJ 486 13.7 x 15 with .080 cup
Prop #4 OJ 445 13.7 x 15.5 with .090 cup (I think OJ said this will raise my rpm by 300-400).
It doesn't seem like ACME has an in between prop. Looks like the extra cup is what I'm going to get if I stay with ACME. The OJ props is CNC. Prop #3 spin correct RPM? I read on Michigan Wheel website that prop to hull should be at least 15% but 20% (of diameter) is better from prop to hull. I think ACME said only 10%. Who's right? Should I just stick with a 13.5 prop since the is no cavitation now? I know stock prop was 14" diameter but it was also a pancake prop, not sure if raked props make more cavitation. If I stay with ACME and go to 13.5 the prop is #1630. Not sure whats spinning faster, these props or my head!