LA roller cam ideas

I have an '89 ram with a tb fuel injected 318. My question is: is there an aftermarket towing/rv cam out there for this that retains the roller lifters? If not can i advance the existing cam to maybe improve performance. Emissions are NOT a concern where i live. I really hate to reuse a stock smog cam, but will if i have to. Thanks for any insight from all the experts out there!