good engine selection

[Ketamine84]

New to the forum, looking for some advice. I have a 68 c10 with new paint, interior, and a ridetech coilover suspension on cpp disc brakes. it currently has a 355 with a tremec t5, and 373 gears. Was thinking of upgrading to a 383, 406 or maybe even a 427. what do you guys think? I dont plan on racing it, just want something to pin me to the seat every now and then. Looked at white performance, so far they seem the most bang for the dollar. Any help would be appreciated.