[yardbird_pro]

was having a good year and then boom!! pop goes the pontiac so now should i build another 455 (cheapest) or go with a 400/461 kit? i have a 69 400 out of my lemans that already has the work done to it(30 over) or i can try and find a 455 (30 over) and so far no luck.. what will a 400 stroker gain over a 455 ?? i would like to go faster ..
my heads are still usable (6x) but im planning on building a set of 68 16's for the new motor.. any input will help..

[71firebird400]

Personally I like the 3" Main of the 400 stroker.

I think on a dyno there would be nearly no difference between the two, build whatever is cheapest for you would be my advice. (In my case that was the 461)

[440GP69]

3.00 or 400 main all the way !!! way stronger than the 455

[yardbird_pro]

well it would be cheaper if i could only find a 455,, i have the 400 , i did like the 455 but in the end after all the work on the 455 plus the $$ for the block we are only talkin about $500.00 cheaper if that. does anyone have any real # to compare the two?? thanks for the replies..

[Mo]

Jagtec has a nice 400 stroker with eheads, solid roller, dominator, 2 bolt stud mains, etc. Runs 9.80'-10.30 at aprox 3100#. HTH

[440GP69]

well you just popped the 455 maybe its time to invest in some good rods a good 3.00 main 4.21 or 4.25 crank some light weight pistons! its worth it! i have 1800 just in crank rods pistons and pins!, granted you don't have to get carried away but if you are going to add a bunch of compression and make more power then the 400 based stroker will be cheaper in the long run IMHO, the 455's big main's really don't like high rpm and high hp like the 400 mains do.

[steve25]

First with any CID new motor you need to adress the problem of what POPPED in the old motor and not repete that. Was it Rods?Going faster only a couple of times and then blowing things up is totally no fun!
I would sink all my funds into a stout short block that I could make a safe 700HP and 7500 rpm with even if I had to run stock heads for a while!

[Mr. P-Body]

As stated, 400 block, 4.25" stroke, MUCH stronger (physically) than 3.25" mains. The crank in the 455 is "stronger", but the crank isn't the weak link in the chain, the block is. Because the "hole" down the middle is smaller, but centers are the same, more "meat" in the 3" main block. More meat - more strength. The 3" main of the 400 is still 1/4" larger than the mains in a BBC or Chrysler Hemi, making crank strength a non-issue.

Also, bearing speed is lower, generating less heat in the oil. The 2.2" rod journal of the stroker crank offers a much more desirable result as well, again, due to bearing speed. The BBC journal also brings more bearing options to the "table".

FWIW

Jim

[yardbird_pro]

i know what popped my 455 and hope it wont happen again,, dropped a stock valve head while doing a burnout (not a pretty sight !!) i will try to post sum pics sumtime,
over all i think the piston and block may be the only things that may be toast. but i will have to have the rest checked out.
thanks for helping me make my mind up on this..

[BILTIT]

What damage to the block? May be cheapest to get a new piston and sleeve the cylinder.

[Region Warrior]

Originally Posted by Mr. P-Body

As stated, 400 block, 4.25" stroke, MUCH stronger (physically) than 3.25" mains. The crank in the 455 is "stronger", but the crank isn't the weak link in the chain, the block is. Because the "hole" down the middle is smaller, but centers are the same, more "meat" in the 3" main block. More meat - more strength. The 3" main of the 400 is still 1/4" larger than the mains in a BBC or Chrysler Hemi, making crank strength a non-issue.

Also, bearing speed is lower, generating less heat in the oil. The 2.2" rod journal of the stroker crank offers a much more desirable result as well, again, due to bearing speed. The BBC journal also brings more bearing options to the "table".

FWIW

Jim

Yep.
Sold my 455 blocks years ago, but kept 2 of the N cranks