ive ran the he-351 and a 6 blade 60mm w/a 12cm housing back to back mountain towing 9k lbs. they ran very simular, the 351 cooled egts maybe a little better but i think drive pressure becomes an issue over 40psi boost. i like them both for quik spooling and good power, ive tested larger housing and found once the turbo is out of its map exaust size is irrelevant . big housings suck imo