318 LA roller block questions

Hello guys.. I'm technically a B-body owner but this forum is amazing so here i am :) Just a quick question or 2

I just picked up a 318 of FB (have never run a small block before though it would be fun to play with) What i ended up with was a '85 LA with the spider mounts in the valley but a flat tappet cam in it. It was a truck motor, i did some research and couldn't find much other than this is possible to find now and then.

I was mainly wondering if there is any reason to avoid using this before i start dumping money into parts? Plan is to get heads/cam/intake setup for this year to get the car working and sorted (hasn't moved since 1978, going through every bolt) Then hopefully a 390 next year.
P.S. I don't plan on a massive cam as it will be a street car to have fun in and beat on, not heading to the strip.. Any issues using factory roller lifters upto around .525? thanks guys.