I'm looking to get gear drive timing and I don't know if my 305 has a roller cam it's a 1987 5.0 carb

 

GM started using roller lifters in 1987. If you have the engine apart you can always look inside. There is no real advantage to going to a gear drive, but there are some disadvantages including transmitting all crank vibrations to the camshaft which can cause variations in cam ans spark timing. A double roller chain would be a better solution. Of course it may be that you just like the gear whine.

 

I love the gear whine that's the only reason I'm doing it I'm also wanting new headers I just got a spectra dual air intake I'm going to be taking out the back seat and just doing 4 bucket seats with 6point harness then later mild cam new heads intake and carb and just maybe a 100shot of nos the but for now I just need my trany fixed