I just purchased a 1984 FXSB Low Rider. The bike is a basket case. I am doing a complete frame up build. Not looking to bring the bike back to stock. Here is what I have done so far..

S & S 103 cu shovelhead crate motor (keeping original)
Baker 6 into 4 tranny
New sheet metal and paint

Now, here is the question..

I'm looking at a Primo open belt drive, brute IV, it lists fitment as 1970 thru 1978 shovelhead. what changed?

Baker says I have the same output shaft on tranny thru 84, and same case

S&S says same crank on motor from 70 thru 84

I don't know why this won't work with the exception of electric start. However, Primo says I will need to update to Evo style starter anyway, so this factor is eliminated. Am I missing something.

This is my first build, don't want to make a bunch of costly mistakes

Thanks for any help you can offer

 

Your in complete custom fit as you can find what works territory now forget anything that has to with model year as it doesn't count anymore . Off hand I'd say it will fit but the question is still the starter issue , late model starters have different gear drive & tooth count than shovels did and the way they engage the clutch shell is spaced different too . Better do some serious digging before you spend money on big ticket items for compatibility issues .

 

The only justification for the Baker 6 into 4, is you can reuse stock primary,clutch,starter etc...as soon as you start changing these items...doesn't stack up. For less than the price of the Baker, you can get a Rivera-Primo shovelhead conversion kit, which has everything you want...ready to bolt on and go.

http://www.jpcycles.com/product/603-150

 

I am familiar with the primo conversion kit. I decided against it because I did not want to loose the kicker...I know it is just there for looks with the 103, but I want it there none the less. With primo primary drive, and 1990 era starter, I think I have pieced all of this together, assuming I have room under the oil tank for the new starter, but primo conversion kit uses the same late model starter, and I believe their 6 speed is taller than the original 4 speed, which is the same height as the baker. I will know more when tranny comes on Friday. I will let everyone know how this turns out. All I can say is it's goin to be fun, well maybe?!?!?!

 

I have both the baker and primo trans...the baker shifts sweet but it still has the 4 speed clutch release and the tapered shaft. The spined main shaft and ball and ramp clutch release is trouble free and more suited to the 103...not to mention a LOT cheaper even after adding a $400 kicker kit....Good Luck