Can anyone tell me what I should expect to spend on rebuilding the top end of 500s? I am at about 300 hours and think they are floating at WOT.

thanks. Dan

Option1: New springs and lifters. $750 per motor in parts. Heads stay on motors. 5hrs labor per motor. In and out in one day.

Option2: Heads off. Pocket port heads. Cut 3 angle valve job. Re Lap valves. New seals, springs. New lifters. $850 per motor in parts. 6hrs plus $400 per motor. 1 week downtime.

those are ballparks.