HD 255 & Andrew's 48
 

Sorry for another cam question guys but hopefully mine is pretty simple. These 2 cams are going to be pretty much the same except I would think the bike would run a little cooler with the 48 because it's a non emissions cam is that correct?

These cams are similar in that they are torque cams, the engine heat comes from the fact
that it's an internal combustion engine. The exhaust has heat because of combustion, and has
to pass through a Catalytic converter, that creates more heat.

Toss a coin. If you are looking for torque either one works well.

Do not put 255s in a 103+! If it is a 96 and ya can get some take-outs cheap enough ($0-50) than OK.

I just put the 255's in my 96" and it pulls hard and after spending a little tuning time I'm running fairly cool. Great cams.

They are going in a '12 Ultra with a 103 probably going to go with the 48. I thought about 222's but I don't think they are going to be worth the price difference

I wouldn't look at the SE255 for a 103. IMO and it's just that.... the only SE cam that I would use is a 204 with 1.75 rocker arms and that is not a true stump puller it's a mid range cam. The 48's were designed for the 96's and the 57's were designed for the 103's. Personally I would drop to a .030" head gasket and go with the 57. I may ride different than you do but that 255 shuts off way to early for my tastes.

How often do you run over 4,500?

The 48 would be my choice simply because it will carry out the TQ curve a bit further and has a bit lower CCP to deal with. However, if you don't see 4500 rpms often, the 255 is a torque monster in a 103. You should have compression releases with either cam. Also upgrade inner cam bearings as part of the project and take a good look at your tensioners; early or late model, still worth a look-see. You will need a fuel management system and a good tune with either cam as well.

Good summary! Part of where the 255 gets torque is from an early exhaust valve close. Consequently it's a bit more sensitive to gas octane, and generates more heat. Mine was tuned in Oregon with 92 octane gas. Now in California the best we can get is 91 octane...and sometimes I swear it's not even that. Anyhow, With these caveats, I'm happy with mine.