panhead top on shovel bottom

[chopmafia777]

hi everyone. i am a young 21 year old college student that has a very strong interest in the older harleys. they have character, and i appreciate their mystic that i find in them. anyways,i decided to join this site to find some help. i have zero people in my life to help me with this stuff and i want to learn. so, iam going to have some questions to give to you all. i would greatly appreciate some advise. anyways, i am going to post my first question on here. i have a 80' 79' shovel bottom. i would like to run some 61' heads on my shovel barrols. other than having to convert them to outside oilers (since they are pre 63' pan heads) what else am i going to have to take into consideration, IE: pushrods, valve bindind ( difference in shovel and pan cams) if any, ect... i want to know all there is to know about taking on an operation like this. any words of advise would be appreciated. i am going to post this in the panhead forums as well. please bare with me as i havnt been into this stuff very long, and really want to learn from some veteran mechanic/bikers. thanks alot in advance!!!!!

[lplugw]

You'll have to use pan barrels andbore them to fit 80" pistons. Pan/early shovel (74")stroke is 3 31/32", 78 up (80")shovel is 4 1/4". If you use 74" pistons your compression ratio will be like 6:1. Very low performance.
Push rod/valve geometry and cams are the same for shovels and pans. The only difference between a pan headand a shovel head besides the obvious appearance is the shovel head had a head bolt relocated to streamline the intake port and split it like a"vee"and get rid of the "tee" shaped passage the pans had. Flows better.The new aftermarketpanheads available actually must be used with shovelbarrels and shovel intake manifolds. They also tend to look like shovel heads from the left side of the bike.
Once you get those heads of yours set up for the side oiling, the rest will be easy.

[lplugw]

Wanted to correct myself. 80" pistons on 74" flywheels=low compression ratio, 74" pistons on 80" 'wheels will hit heads or valves.

Point is, don't mix them.