Hey all,I just finished my rebuild on my 420A. I kept everything stock because I was hurting on money at the time. Ended up having to buy a refurbished crank because my 4th rod journal was eggshaped, bought a refurbished rod as well for that cylinder. Haven't gotten everything hooked up yet but its at least in the car (took 2 hours to figure out how to drop it in). The one thing I did replace better than stock were my piston rings, I got the Total Seal Gapped Molibdeum sp* Coated piston rings.

Anyways my question is what would you guys suggest would be a better performance mod to do first. I was thinking of putting in a 50-100 shot nitrous fogger system for some quick hp but am not sure how much the new rings can handle. If not the nitrous then for roughly the same price I can frankenstein my own turbo kit together and bolt that on instead.

Any thoughts/opinions are appreciated

The rings aren't really your concern. It's the ring lands - the cuts in the pistons where the rings sit. Too much stress on those stock pistons and you're likely to break a ring land, which will result in a severe drop in compression.

Basically, you're stuck with stock levels - <75 shot - until you can rebuild it for the abuse.