Dart big M 454 block with mech fuel pump. Dart big M heads.
8.75:1 comp
This motor was purchased from ron sporl and built as a 420 replacement.
Roller cam, Crane gold roller rockers
have dart single plane intake or mercruiser dual plane.
800 cfm Holley
Closed cooling system
Bravo bell housing and coupler.
Complete with Gil manifolds and all accessories,
Not sure exact hrs...but under 100
$4500 Obo
Will sell as long block or complete.

Edit, just removed intake and found to be a flat tappet cam, very good shape but not a roller.