Lookin to put big bore barrels on my 82 Shovelhead and wanting to know what needs to be done to my engine case and if I can use my stock heads. And could someone suggest a good cam for low end torque.

 

The engine case and the heads need to be machined to accept the 3 5/8" bore barrels.

 

Cases & heads have to machined a bit for the cylinders to clear , no biggie at most shops .

Best shovelhead cam are the VThunder series by Competition Cams . They are designed for hydraulic lifters and are strong low & mid range cams , power ban comes in around 1200 to 1500 RPM and pulls great till 4000 or so . But you will have to put in a hi lift springs .

Look at the SHV 4010 or the SHV 4020 , the 4020 is strong hard hard pulling cam for a stocker rolls on strong . It's an excellent cam for a heavier bike for loads . The 4030 is a hot dog for 80" , likes open pipes and a bit more carb , I use this one in lighter bikes for guys who like to run it a bit harder .

Andrews & Crane cams all need 2500+ rpm before they begin to wake up a bit they all tend to hi rpm orientated the low and mid range isn't there .