ThInking seriously about buying an alpha ss, if I can find one, to replace my alpha one. What kind of gains or losses could or should I expect to see. My boat is a 20' concord with a mild SBC. On a good day I can get it running in the lw to mid sixtys. I'm getting ready to start tuning the carb a little to try and gain a few mph and I ave heard that the alpha SS drive is good for 5-8 mph bolt on. Any feed back would be appreciated.

alpha ss changes prop height. raises it by 2 inches, i think. measure where yours is and do some research...

I'm aware of the physical differences but I was more curious about people's experience with actual performance gains when using the SS drive

Performance gains all depend on prop shaft height. How many inches below the hull bottom to the center of your prop shaft with the std Alpha?

If the X-Dimention is agressive, you might not gain much, if anything by going to an Alpha SS. (If I remember correctly the SS is 2.75" shorter from input to propshaft)

I've got an '86 22 Pachanga, installed an Alpha SS and lost speed as the prop shaft was way too high with the SS, The X on my boat was cut very high from the factory.

My last boat was a '88 Baja Sunsport 196. We did a back to back comparison on the same day within a couple hours and saw a 5 MPH increase with the SS drive. The boat had a tame 383, running 74 with the SS.

i dont know what my X dimension is but im gonna say its on the low side, back in the 90's concord built two boats using the black hawk drives and had to raise things up to make it work right. my boat uses the same hull that these boats did but my drive is at the "standard" depth for use without the blackhawk so im hoping that the extra 2.75 inches will allow me some more mph. im thinking that prop shaft height is more important than the actual X dimension as far as this is concerened so i may go do some measuring here after a while and see where im actually at and follow up later to get some more opinions.

was also wondering if anybosy knew about parts availability for the SS. hate to buy one, break it and not be able to fix it

if you can find one you going to pay in excess of 2 k for one.. the parts in the upper is the same as the standard upper gen 1 alphas..the center shaft is nla so that part is out and the lower usaes the same parts as the cle (bridgeport 2.5l outboard) lower case..

I had a Glastron Carlson CVX - 18 with a lot of HP. The drive was mounted TOO low - the cavitation plate was 1/2 inch below the pad bottom when the drive was all the way down. I installed an SS and gained 10 MPH. the next winter I rebuilt the transom and raised the drive another 2 or 3 inches. This brought the prop shaft to 3 inches under the pad. I gained another 10 MPH. This boat had so much HP per weight that with the stock drive I could cat walk the boat with a light gas load and just me on board.
The engine was not even close to stock

x dim is measurement from crank center to bottom of hull. that doesn't really matter. what does is prop center to bottom of hull. that is what i meant by do some measuring and do some research. the perf gains/losses are ALL based on where the prop ends up. from the sound of it, at the price for an extinct drive it may be better to change over to Bravo where shorty drives are common and spacers are avail to put the prop at the sweetest spot. do some searching here on x dim. also on screanandfly. they are an outboard oriented forum and with jack plates there is probably a lot of info on prop height. i looked on ebay. no alpha ss drives for sale. means very few anywhere...

A.O. Razor is real big on this subject. and he sounds like he knows what he is talking about. get some measurements and shoot him a PM...