on the customs piston and how long of the rods to use i can help maybe ? . i do not think you can beat the price on the H beam rods for the money i have used many sets and think they are a great value . on the heads they could work. here some things you may want to do first. 1wash and check for cracks. 2 do they need guides ?2 SS valves. 3get them deck .4 rotators eliminators.5 cut heads for big valves. 6 new guides. 7 set heads up for valve springs. 8 cut down guilds for PCseals and hi lift cam. 9 valve job 3+ angle .10 bowl work.this is not in the order how it would happen. this is all stuff that the heads may need. so you will have alot of money in them ? there is things i did not add in hard EX seats, spring keepers, spring retiners, new rocker studs 3/8 pushrods guilds ? it may have them on the tall decks they did have 3/8 pushrods so you will want to get a price on the work and parts. you may find out for not alot more you can buy some new heads that will make more HP and not to much more money if the heads you have need a lot of work. all parts will be the same price for the new head casting or you old casting