Need the facts (From the OMC xperts)

[Charles Salsman]

There was test reports back them for that boat, probably with a 115 merc on it as shown in the pic. Just do a comparison of that with the 135 on it...


, the gearcase will hold you back, it wasn't designed for speed, very blunt in the front. Normally, I wouldn't tell you to put a nosecone on it till you were over 75mph, but on that old case I would do it anyway, no need to change it, just reshape it.... The post 79' gearcases were much better and I have run them close to 80 with out a cone but that was pushing it. The 135 should get you into the high 60's or 70's, it has a taller gear ratio than the later V4's, find yourself a 14X22 Chopper and have it rehubbed and go from there.
Don't be afraid to spin it over 6K we ran them there all the time.

--Yes, the reason I am looking at the gearcase first is because of others (and you) mentioning this fact in other threads...
--- Ive contacted Ranger, they said they have no further info, other than that picture.
--Ok, this is good info. I havent looked into the particulars of nosecones, is there a certain type I should look for?
I was also considering the Boyeson Reeds.
What octane gas should I be using, and what spark plugs do you recommend?
(Im not using those 73 heads, I just bought them for 'provisional' purposes in case I want to get deeper into modifying this)

The prop I was considering was a 13 1/4 x 24 "Raker", but Im going to follow your advice on the Chopper 14x22... I didnt realize I could divert from the 13 1/4 dimension.

[Skoontz]

I found that running a 12" step bottom on a Vee, and an additional cantilever, which stuck the motor back 8 more inches, and then jacking the motor 4" higher than stock propshaft depth worked best. That was on a '79 140, and I ran a 28" chopper at 5800 RPM. Higher R's on that motor actually ran slower for me. Speed danced between 72 and 73, Island Lake Illinois Police radar under the 176 bridge.

Thought i would toss that at the fan...

[Tomtall]

Charles - Very cool project you got there. I remember when Ranger came out with that boat. Listen to Bill Gore. The man worked for OMC and knows his stuff about their engines. He probably doesn't remember but he helped me out way back when to get a GT150 to run like stink on a Skeeter bass boat. If your lookin for a great nose cone with a good fit go to http://www.hydromotive.com/main.html
They also have a prop that would work VERY well for your set-up. It's a desighn of their own based on a small chopper and can be hubed for your application. I've run their props on many a bass boat set-up and they blow the rest away

[Charles Salsman]

I appreciate all of the response you guys have given me so far, seriously. I no longer feel as if I am going through this alone & blindfolded! I am glad I decided to register here. I have lurked here for a while now, reading up on various topics, mainly about the old OMC crossflows, so I know to trust the words of Mr. Gohr!

Ive got the factory service manual and it lists this gearcase as having a 13:25 gear ratio. They show 2 different models - 135683 & 135643. It looks like the 643 (my model) came with pt&t, 12A stator, and stainless 13x19 prop. They list Champ. UL77V plugs, or L77J4 for sustained slow speed operation. I just want to make sure that's still applicable, as the UL77V has been discontinued, and crosses to a QL16V plug.

I got some feedback from another forum about my boat, it is the same as the Allison XST. The XST was listed at 700lbs, came without carpet, had 1 livewell instead of 2, and no doubt did not have 80lbs worth of hatch-lids
Apparently in the mid 70's, Allison did not have a presence West of the Missippi River (According to an article I saw on Allisonowners.com scanned from an old magazine).
Speculation- I doubt Ranger wouldve become the monster that it is today if they had not hooked up with Allison that year. (At least FLW had the decency to pay them for their technology instead of trying to copy it) I guess the difference was that Ranger's target audience was less about performance, more about fishing, and Allison is ALL about the performance...

[Charles Salsman]

If your lookin for a great nose cone with a good fit go to http://www.hydromotive.com/main.html
They also have a prop that would work VERY well for your set-up. It's a desighn of their own based on a small chopper and can be hubed for your application. I've run their props on many a bass boat set-up and they blow the rest away

Which prop is it?

The T-3x sport is 14 1/4x(22-34)
The T-4x is 13 3/4x(22-34)
The Quad IV-x o/b is 15x(22-32)

Of those 3, the T-4x seems the most appealing because of the claims of improved handling.
Also, I read some info from a guy with an 76 Allison XST that used a 150 Merc and '26 pitch stock chopper'

Ive been trying to find out what exactly a 'chopper' is, and what the different types are, such as 'round ear', 'small ear', etc, etc. Also, is a cleaver a type of chopper, or something entirely separate?

Ive ordered a couple of books from Amazon that will hopefully enlighten me a little bit.

[Skoontz]

Chopper props were originally sold by Mercury and you had to respline them to work on OMC. The blades are long and thin, rounded on the end, kind of look like a Basset Hound dogs ears welded to a stainless hub. They are made to lift the nose.

[JohnsonM50]

A cleaver is basicly the kind with the straight trailing edge and pointed [not always] tips. Choppers are similar to dog eared in appearance.

[Tomtall]

Thomas Burgland gives some sound advise on the differnt prop styles and set up for a UIM race class (but also applies to your situation) at this link. http://www.ocke.se/motorboats/boating_tips/index.html

As far as a 3 blade or a 4 blade design I would always talk with the person selling the prop for their input. On the Bass Boat hulls that carry a heavy load the 4 blade seems to give a better hole shot but I have seen a reduction of 1-2 mph on the top end. Stability and steering torque are more favorable with the four blades. I am no prop guru by any means but am giving you what I have experienced after a lot of testing on the water with both styles.The Cleaver style props on a bass boat hull usally don't perform as well as a Chopper style.

[Charles Salsman]

Thanks, Im not sure how much bow lift I'll need with this hull... In addition to a pad, Ive got tunnels, which are supposed to provide some degree of lifting, if Im not mistaken. Here is a link with drawings of what the hull looks like. http://www.google.com/patents?vid=USPATD244518

Do y'all think since it's got 'sponsons' it'd quailfy as a Tri-Hull racer?

I do have the number to a shop in Tenn. that I plan on calling, was told he has much experience with these bassboats.

We had some decent weather today, but I am not done yet with rigging, and Im waiting on the UPS man to get here with a new 'Vernatherm' thermostat, old one is sticking. It might be another few days before it warms up enough to get out there and do some testing.

[Tomtall]

The thing that cracks me up when I watch the guys in our area with their $50,000 bass boats they bought at the local Bass Pro Shop store is they have a rooster tall 100' long behind their boat trimmed to the moon trying to get the bow to carry and going 65 mph. Keep the motor trim neutral with a laid down rooster tail. If you need a prop with more rake to get the bow up to do this, so be it.