Forgot, if it's a 71-76 it has 906 heads (good) 77-78 had 452 heads. (a little better) They are the same except for flatter port floors and inductioned hardened valve seats for unleaded on the 452's.. Both have 90cc chambers. 2.08 intake/1.74 exhaust valves. The compression in in the low 8's for both. Cast pistons, cast crank, forged rods. Pistons will be needed for 10 to 1 or higher. If it's a 71 block, casting number ending in 230, it has heavy duty webs and is the best 400 block to get. Very scarce..buy it! The late cop cars had chromed valve shafts and roller timing chains. Don't know about motor home motors. Good luck! Joe again -- [Non-text portions of this message have been removed] ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html. b7yoMz.