a 235 should sound like a quiet, well oiled sewing machine - if it doesn't make any noise at all at idle or lower revs, you've got the valves too tight - you may also not be getting good oil flow up top at higher RPM's - check the book and readjust them [well warmed up] to .006 intake, .016-.018 exhaust

Bill

Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics