Its a 2 bolt main with all ARP studs in lower end, eagle rotating assembly. work was done by hughs in Fallon nv standard bore and stroke he balanced it also. heads are ovel port he also checked them has Howards custom ground cam pulls from 1500 to 6500 and loud gear drive. Pollished tunnel ram single 4bbl with a holly 750 double pumper. Not sure on the .