Looking to purchase a cutlass with a rebuilt 455. I have some of the specs and work done to engine. Seller states it's a 450 HP engine. Would appreciate any input. Trying to see if these specs equal what is being stated.

74-455 with TRW aluminum forged pistons .030" over
Rods were balanced and polished
C-heads- stainless steel valves 2.072" intake and 1.71" Ex. Decked .030, crossover passage filled, hardened seats, new guides.
Lunati street/strip cam with .517/.541 lift & 231/239 duration

Edelbrock Torker II intake
Hooker Headers and flowmaster duals 2.25"
Holley 750 carb vac-sec. w/ electric choke

 

Depends.....how much nitrous is he spraying?


To answer your question. No. It is not.

 

What would be your guestimate HP?

 

Carb? Intake? Headers?

 

I say 400ish

 

Holley 750 carb vac-sec. w/ electric choke

 

X2, especially if you don't know what intake and headers are on it. It's not 450 one way or another.

 

Headers and intake are now in description

 

Ask the seller to see the dyno sheet that proves this engine puts out 450 HP. It's really not that hard to achieve with a 455, but unless the owner actually ran this engine on a dyno, it's purely speculation. The cam used looks pretty tame. Was there any port work done on the heads? Was the rotating assembly balanced? Is there any transferable warranty on the engine work? Will he provide all receipts for parts and machine work? Did the builder provide a blueprint data sheet? These are just some of the questions that I would require answers to, before I pulled the trigger. IMHO the limiting factors on this engine would be the stock rods and heavy TRW pistons.

 

No dyno sheet. Computer dyno software. Rotating assembly was balanced.

Heads:
Wedge/ Pocket porting/ unschroud valves/ raise port roof/ and polish iron "C" casting heads w/ exhaust crossover passage filled in.

Has machine work receipts. Engine was built by seller, no transfrable warranty

 

i'm no expert but i would say over 400

 

Huh Dave?
He asked about the hp, not how high he can spin it. Not sure what "limiting factor" of the weight of the pistons and style of the rods would have to do with the hp output. Guess I don't understand your statement.

I did a .040 over Ga headed 455 last year. The results are on here;

2.07/1.68 valves
10.0:1
RPM intake
850 Proform
Roller cam, 231/234@.050
Flowtech 1 3/4 headers

413hp/496tq.

Yours might make the same, don't think it will make any more than that.
Like Chadman said, 400ish.