REDWOOD

Hello I am new here and I am currently working on a body off restoration on an 84 t top cutlass supreme that I am installing a 68 455 in and would appreciate any help I can get on parts or modifications that are going to be necessary such as long or short water pump or anything else that's going to give me clearance issues

joe_padavano

The only external difference between the 455 and the 307 that came in that car is the deck height. Engine length is the same. Use the water pump that matches the accessory brackets and pulleys.

REDWOOD

Thanks that helps a bunch and I'm planning on putting the complete march serpentine system that comes with ps pump, ac compressor, alt and all hardware and brackets but it comes with the long pump and not sure if that's gonna give me clearance issues

joe_padavano

Why? First, it's not a real serpentine system because it uses a conventional rotation pump. Because of that it requires three or so idlers to maintain pulley contact, which typically results in more friction and HP loss than the stock V-belts. Your money, your call, but $1700 is a lot to pay for bling with no performance benefit.

CRUZN 66

Welcome to the group... Take caution on valve cover selection to avoid clearance issue with the AC/Heater box...

REDWOOD

Good question really I'm just now starting to put the motor together now that it is done at the machine shop and I dont have any of the front components so was just looking around and it seem like pretty decent complete kit yes lil costly. Trying to maintain the sleeper look as much as possible motor is built to be in the neighborhood of 550hp or better