Difference in 3 link chassis

[KG23]

New to the modified scene. Looking at buying a car to race in the UMP B mod class. Is there any difference in the way cars are built to run UMP rules as compared to say a car built to run Sportmod rules?? I realize there are different rules amongst the classes but just wondered about the chassis themselves.

[CoastieMod]

the only difference that i know of is the right side frame rail length. you also cannot run aftermarket lower's. there are a couple minor differences but i have not seem them checked or enforced where are you running the b mod at? i know in michigan a lot of the ump mods run lift arms and you can't run them in the b mods. atleast the merritt/mt. pleasant b mods.