I have an '87 Suburban "C" code.. In reading and reading a ton of threads, I believe the "J" code heads are the ones to go with.. Although I've heard of the "J"s cracking as well.. So just wondering if there is a specific casting number and/or year that has had the greatest success rate as far as using 6.2 heads.. I'm also running a Banks sidewinder and I'll be using the ARP head studs.. Also, can anyone recommend a place to get heads from? Is there any place that builds "new" higher performance heads for the 6.2's?