View Single Post
  #3  
Old 11-02-2021, 09:21 PM
Douglas Willinger's Avatar
Douglas Willinger Douglas Willinger is offline
Senior Member
 
Join Date: Dec 2017
Location: Rocky Mount, North Carolina
Posts: 178
Default 455HO suggestions

A 1972 455HO, like any factory Pontiac 455, combines a large journal (3.25") with 4.21" stroke.

Swapping in a modern, better-quality reciprocating assembly is imperative.

You may de-stroke to 4", or stroke to 4.5"

Butler has a range of options:

https://butlerperformance.com/c-1234...55-blocks.html

Closet in size is the 4.25" option.

Eagle may be the most widely used, but Scat is superior.

The best bang per buck for crankshafts and rods are SCAT and Molnar. For rods definitely go with MOLNAR. With the 2.20 crankshaft rod journal, use the BBC 6.8" or 6.7" Molnars.

Quote:
Originally Posted by big matt View Post
I have a 1972 yb code 455ho. Its the original engine to a 72 gto coupled to a th400. I want it to retain the factory heads, and appear from the outside to be stock, even valve covers, except for the fact it will have black long tube headers. It will have a full 3", rear exit exhaust.
My gut says put a modern rotating assembly instead of reconditioning the rods, and using a oem crank. Stroker kits worth it? I would like to hear whats good in 2021. Eagle, Butler?? I need to Pick out roller cam that will work with the iron heads and oem aluminum intake. Head wise, i am looking to leave them mostly alone except a clean up cut, valve job, and recommended springs retainers. Perhaps some crower enduro rockers. Would prefer to keep it on premium pump gas if i can.
Also an opinion on the converter. Rear gear will be a 12 bolt, somewhere around a 3.42 gear. 27" tall tire. This car will be used as an aggressive weekend cruiser. Maybe 2000 miles per season. I want it to straight up snap your neck. Chime in if you have any opinions. This kinda is a blank canvas. I am willing to spend some coin. This is a one time deal. I want it to run. Thanks

__________________
1970 Lucerne Blue Firebird Trans Am, deluxe blue interior. Original Ram Air III, M-21, 3.73. Being built as a 4" stroke "434" with SR 614 Ram Air IV heads

1972+ Lucerne Blue 4-door hardtop "what if" T-41 Le Mans Sport GT/Grand Am concepts. Equipped with future 3" journal "455 HO"/"what if" prototype "SD 455".
What if GM had continued production of the 1970-72 GM A body somewhere in the southern hemisphere?