i have a 1979 fxef fatbob with 1340 shovelhead all stock,how big off a cam can i go with out doing any mods to the engine

 

what compression is your engine? 8:1 or 7:2:1?? if its a 8:1 theres several choices --

andrews "J" its a bolt in cam not much of a cam though -- andrews "A" the new "A2"

if its 8:1 i have a used sifton #116 its a excellent cam for electric start engines

IF you can find a old school sifton 412 thats the best choice.. it depends on what your looking for in power.. low end? mid and top end?

the sifton cobra #112 is a really good cam its pulls from 2500 to 5000 rpm the sifton cams of today need to have the gear timing checked--

in your case i would say the andrews "A2" soild or hyd -- make sure you change the tappet rollers

i run a lienweber L3S in my 80" but it needs head work and springs --

--- http://www.andrewsproducts.com/motorcycle-parts/catalog ---

 

Don't know the compressing, just got the bike 5 days ago