455 with Early 400 Crank Build
#1
455 with Early 400 Crank Build
Hey everyone I have a few questions and hope you can help me answer them.
1- I am building a 68 455 for one of my 66 cars and was wondering if I can install one of my 400 forged cranks into the block and use stock 455 rods or do I need to use the longer 400/425 rods.
2- The 1966 B heads that I plan on using are engine # N723613 and there is no T at the end indicating from a toronado motor so I am unsure if they are 39 or 45 degree heads. Obviously the 455 block will have a 39 degree lifter bore angle and if the heads are originally 39 degree will it affect the top end. Usually I have B heads with engine # V indicating 442 heads with a 39 degree angle but I am unsure of engine # N first set I have owned.
Any help would be appreciated as I hate to start machining and find out that the heads will not work or I will have to spend more money drilling the push rod holes to be acceptable. Thanks.
1- I am building a 68 455 for one of my 66 cars and was wondering if I can install one of my 400 forged cranks into the block and use stock 455 rods or do I need to use the longer 400/425 rods.
2- The 1966 B heads that I plan on using are engine # N723613 and there is no T at the end indicating from a toronado motor so I am unsure if they are 39 or 45 degree heads. Obviously the 455 block will have a 39 degree lifter bore angle and if the heads are originally 39 degree will it affect the top end. Usually I have B heads with engine # V indicating 442 heads with a 39 degree angle but I am unsure of engine # N first set I have owned.
Any help would be appreciated as I hate to start machining and find out that the heads will not work or I will have to spend more money drilling the push rod holes to be acceptable. Thanks.
#2
L69, welcome to the site! I've always been under the impression that early 400 and 425 interchange then late 400 and 455 will interchange. The crank will physically fit, but I think the problems will come when you try to mix the rods/pistons but someone who knows for sure will speak up soon.
John
John
#3
L69, welcome to the site! I've always been under the impression that early 400 and 425 interchange then late 400 and 455 will interchange. The crank will physically fit, but I think the problems will come when you try to mix the rods/pistons but someone who knows for sure will speak up soon.
John
John
Thanks John
#4
I am assuming that I would have to use the 400 rods with the 455 pistons I have never done this build but it seems like an interesting destroked 455 to 425 plus the added benefit of the forged crank.
#5
You can use a 455 block with 425 rods and pistons; it will become a 425. 425/early 400 rods are 7" long and the piston compression height is 1.61". 455 rods are 6.735" and compression ht. is 1.74. Early stroke 3.975", late 4.25". So you see what has to match up for the pistons to give decent compression.
Last edited by Run to Rund; November 12th, 2011 at 08:19 PM.
#6
I know a guy who did the reverse, i.e. put a complete 455 reciprocating assembly (crank, rods, pistons) into a 425 block (in his '66 Starfire). Not sure WHY he wanted to do that, though I sure like the idea of doing the opposite.
#7
Installing the 425 crank,rods,pistons,simply makes a 425.However,you can have that 425 crank offset ground to 4.25" stroke,like the 455 crank,and use BBC rods.You can stroke it up to 4.2975" without any issues,to get more stroke & cubes from it.There are a variety of rod lengths for the BBC rods.Then find a piston to match,or have a custome set made.
#11
#12
You might have a little less into an Eagle crank,depending on what type of finishing work it will need.I highly doubt you can install it straight from the box,so you need to take the initial cost,plus the cost to finish it,then compare that to buying a nice N-crank,and having it offset ground & finished to your desire.
I can check on shipping,but you will probably have about $200.00 into the crank,once it gets to your door.Then you need to have all the machine work done.I use 2x10 lumber,to make shipping crates for cranks.They weigh about 75-80lbs when packaged.
30" x 12" x 12"
I can check on shipping,but you will probably have about $200.00 into the crank,once it gets to your door.Then you need to have all the machine work done.I use 2x10 lumber,to make shipping crates for cranks.They weigh about 75-80lbs when packaged.
30" x 12" x 12"
#13
I think that it's great that you guys are honest w/ your work prices and shipping, and what another brand would run, other options a person has. I see on other sites I frequent that guys are less apt to come off w/ prices or to let a person know about other options they have available to them. Thanks so much f/ being honest and treating one another correctly.
#14
Just to let you guys know I built a customer engine recently 455 destroked with 400 crank and 7" 400 rods, and he is very pleased. Its was sort of an experiment since he had a 455 block and the internals of a 4 speed 400. Motor was dynoed at machine shop making 419hp 488tq. Total displacement was 438 with a .060 overbore in the 455 block. XE274 cam and Toker on top with a 850 carb. Compression was a honest 9.7-1 and it is a nice street motor. These are real numbers and a fairly mild build but he stated he has had her up to 5800 and all held up good and he felt there was plently more. I told him I only warranty my motors to 5800 hehehe, I know he can do 6000 all day long, heck I have had my 400 up to 6500 recently and it was a blast. Please understand these motors have had all proper machining, balancing, proper clearances and HV oil systems. Good luck to all.
#16
1.You take a 455 block
2.You take 400/425 7" rods
3.You mount those rods to 425 .060 over pistons from egge
4.You add a 400/425 crank and vuala! You now have a destroked 455, actually a 438, its quite simple
Last edited by L69; August 3rd, 2012 at 01:56 PM. Reason: error in piston
#17
455 block, typically approx. 10.625 deck height
400/425 rods, 7" length
455 pistons, most are approx. 1.735 comp distance
400/425 crank, 3.975 stroke
By my math that equals 10.722. What did you do with the extra .100 hanging out of the top? Did it magically disappear? Vuala!
Hmmmmm. I think somebody ain't tellin the truth.
Last edited by cutlassefi; August 3rd, 2012 at 05:14 AM.
#18
Just to let you guys know I built a customer engine recently 455 destroked with 400 crank and 7" 400 rods, and he is very pleased. Its was sort of an experiment since he had a 455 block and the internals of a 4 speed 400. Motor was dynoed at machine shop making 419hp 488tq. Total displacement was 438 with a .060 overbore in the 455 block. XE274 cam and Toker on top with a 850 carb. Compression was a honest 9.7-1 and it is a nice street motor. These are real numbers and a fairly mild build but he stated he has had her up to 5800 and all held up good and he felt there was plently more. I told him I only warranty my motors to 5800 hehehe, I know he can do 6000 all day long, heck I have had my 400 up to 6500 recently and it was a blast. Please understand these motors have had all proper machining, balancing, proper clearances and HV oil systems. Good luck to all.
#19
A +0.060 piston for what engine? Olds,Pontiac,? If you simply transplanted an early 400/425 rotating assembly into a 455 block,you would still need the shorter 425 style pistons.
A stock stroke/stock journal 455 crank,7" 400/425 connecting rods,and 455 Pontiac pistons will work.Been there,done that.Just don't chop the deck down.
A stock stroke/stock journal 455 crank,7" 400/425 connecting rods,and 455 Pontiac pistons will work.Been there,done that.Just don't chop the deck down.
#21
Really, apparently your math is magic! Vuala! Let's look at this a little closer shall we.
455 block, typically approx. 10.625 deck height
400/425 rods, 7" length
455 pistons, most are approx. 1.735 comp distance
400/425 crank, 3.975 stroke
By my math that equals 10.722. What did you do with the extra .100 hanging out of the top? Did it magically disappear? Vuala!
Hmmmmm. I think somebody ain't tellin the truth.
455 block, typically approx. 10.625 deck height
400/425 rods, 7" length
455 pistons, most are approx. 1.735 comp distance
400/425 crank, 3.975 stroke
By my math that equals 10.722. What did you do with the extra .100 hanging out of the top? Did it magically disappear? Vuala!
Hmmmmm. I think somebody ain't tellin the truth.
#22
Really, apparently your math is magic! Vuala! Let's look at this a little closer shall we.
455 block, typically approx. 10.625 deck height
400/425 rods, 7" length
455 pistons, most are approx. 1.735 comp distance
400/425 crank, 3.975 stroke
By my math that equals 10.722. What did you do with the extra .100 hanging out of the top? Did it magically disappear? Vuala!
Hmmmmm. I think somebody ain't tellin the truth.
455 block, typically approx. 10.625 deck height
400/425 rods, 7" length
455 pistons, most are approx. 1.735 comp distance
400/425 crank, 3.975 stroke
By my math that equals 10.722. What did you do with the extra .100 hanging out of the top? Did it magically disappear? Vuala!
Hmmmmm. I think somebody ain't tellin the truth.
#23
#25
well like i said in a previous post that you clearly did not read I DID use 425 pistons and engine was machined for zero clearance so Obviously it must have been checked,duh!!!!
#26
I corrected the post where it states 455 pistons. It now states 425 pistons. Are you happy now?
#27
Take a minute and read what you've typed before you post it. That's all I'm asking.
Fwiw I don't think you really know what piston you used. Jmo.
#29
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