Small Block & Big Block Chevy Specific - Vortec Questions

I just picked up a set of vortec heads for $200 and am going to be putting them on a bone stock 350 from a 76 blazer.

The valves leak when i pour diesel into the ports but not very fast at all.
So, I was wondering if i could get away with taking the valve springs off and lapping the valves myself and putting on new seals?

Also, i have a new RV cam that I got for cheap 204/214 .420/.432" and i was wondering if i could get away with using the stock springs? This isn't a high performance application but i do want to be able to turn 5500 if I ever need to.

Looking to do whole project for under $350 and i have $200 in the heads, $45 in the cam, and $60 in the gaskets. I have a friend with a manifold and he's gonna let me use it b/c he's getting deployed and it'd just sit on the shelf if i didn't. so that leaves me with $45 i'd like to keep if at all possible.

The cam is fine, well it least it isn't to big, stock vortec's max lift is .495
Have you priced a valve job at your local shops? My shop will do a pair of heads for $35 but I know the dude.

The cam is ok and should pull 5500 with no problem, the max recommended lift on stock vortecs is .470, but a bit more might be able to go. I would deffinatly have the heads checked for cracks, boiled and a valve job, runs about 90$ for the set around here for all that work.