I am upgrading my bike to the SE 103 bb kit (29903-07). I am not sure what the compression level is with these jugs. My heads are SE part# 16500013a which are supposed to offer same compression same as stock heads just cnc ported. I am adding an Andrews 54h cam as well and not sure whether I should buy the SE 10.5 compression pistons as well for this combination. Any info would be great. Thx

 

You can run the 54 either way. If you use the pistons in the kit it will be a little soft . The SE 10.5 advertised pistons would wake it up . Along with that comes the need for a good tune. Someone familiar with higher compression tuning.
IMO .. If you stay with the pistons in the kit? Use Andrews 57.
10.5 pistons,use the 54's.
if you already have the 54's then you could surface the heads .030- .040 and be where they like to be.

 

Thank you. If I use a cometic .30 gasket would that change compression enough for the 54?

 

It will help. But if you pull the heads for the gaskets anyway,you might as well surface the heads .020-.030 while they are off.
Any machine shop can set this up,and resurface your heads. It dosent have to be a Harley performance ,special type of thing.
I have seen a Lot Of these 103-107 54 cam bikes. They always feel better if you can get the compression bumped a little.
Don't get me wrong , it will work good as your asking. But the little extra compression really helps.
That's why Andrews made the 57 , for the factory 103's.

 

Thanks once again. I really appreciate you taking their metro answer. One last question. I think I am going with the 57h based on the fact you said it was better for a 103. Should I still use the .30 head gasket?
Thanks

 

I wouldn't pull the heads for just the gasket.
If you pull the heads. Your back to making the 54 work

 

I am adding the BB kit so heads will be off no matter what. Just want to make the most rideable bike as possible. Where I am not worried about compression being too high, bad gas but still having extra power. Thanks

 

sorry. yes if you have the heads off use the .030 gasket.

 

Thanks for all the advice! Greatly appreciated.