318, made changes, no gain?

4.10 vs 3.90 isn't much, not for the cost of switching.

Cam and valve springs is needed, the converter might be ok. I had a 318 with .030 cast pistons and mp 360 heads milled .030. That motor I spun to 6,500 daily and flirted with 6,800 many times (3 years after the head swap my #3 rod bearing spun),

You might wanna get a custom cam--in fact I have a 2 year old custom cam grounded by Mike Jones in NC. It looks very nice and I have the matching lifters-or you could run new. I be posting some items in the for sale forums later this week. The cam is 220 @ .050 and 111 lbc has .465 lift with 1.5 rockers.