Road Runner Nest

I found a 400 engine for sale somewhat locally...I wanted to know if it would be stamped HP on it to determine if it was a 72 400HP Road Runner engine. I'd like to have the fellow inspect it and report his findings to me. I can describe where the engine casting number is on the lower driver's side and determine the year. On the top pad near the front intake, would it be stamped HP there? It's a bit far to go to whimiscly check, so I'm going to try to get him to.

I'd like to have it, if I can get it cheap...the 440 in my 72 is just fine for me. It'd be neat to have a year correct, or date correct 400 engine.

if the block is out of whatever it came from, the date code is on the side of the block on the passenger side. i believe you should have a letter (i think '66 was A, so should say F) then 400 and be stamped HP after that

landon1 wrote:if the block is out of whatever it came from, the date code is on the side of the block on the passenger side. i believe you should have a letter (i think '66 was A, so should say F) then 400 and be stamped HP after that

Okay, so the designation for HP is on the passenger's side...

This one turned out to be a 76-78...It's good though to know for next time..thanks!

Brian

Im not sure but If they were like the chargers in 72,the high performance 400's had a 4 barrel carb,non hp had a 2 barrel.

Today I was looking through my car Id book,looking up the codes and stuff about my 400.Im pretty sure it could be the same.

Weird thing is i couldnt find the serial number on my 400 where the book said it would be,and whats even weirder is there numbers where the book says to look for on a 440....???

no, on 440s there is a "pad" flat part on the driver's side of the block that would have the stampings, on the B blocks, it's under the distributor, i believe - you can't even see my stamping, due to all the paint and grime. casting numbers are on both sides of the block, the passenger side also has the date above the casting number. there will be other markings as well

hi is a h on pad for 72 400 or a 440

b 1966
c 1967
d 1968
e 1969
f 1970
g 1971
h 1972
j 1973

Hi,

My 400 was recently stripped / cleaned / machined for professional rebuild. It is a matching numbers '72 BB.





There was no HP designation. If it wasn't HP before, it is now.

Ian B.

the HP designation would be on the front "pad" of the motor by the distributor/water pump housing. HP blocks really are no different than any other blocks - if a motor was to get a dual point distributor, a six pack, 4 bbl, etc. it would be stamped HP

my pad isnt' readable at the moment, but when i get it back from the machine shop it should be...clues now pointing towarda 440 Police Pursuit motor, according to the oil pan, cam, and other motor parts....now it will be a "Super Police Pursuit motor"

Is it strictly for Plymouth 400's?

My 400 doesn't have hp on it but it came with a 4barrel carb.

I have an Id book.Every time i look at this topic at night I remember that I forgot to bring It in from the shop.

no, all big blocks - 440s have a distinct flat "pad" where it is stamped, though...don't have a clear picture or i'd post one

landon1 wrote:no, all big blocks - 440s have a distinct flat "pad" where it is stamped, though...don't have a clear picture or i'd post one

I actually meant the "hp" stamp.

nah, think the HP designation was for any block (pry not 318s)

landon1 wrote:nah, think the HP designation was for any block (pry not 318s)

Thats weird and interesting.

pretty sure they pry would have stamped 340, 360, 383, 400, 440, and possibly 413 and 426 wedge engines (max wedge are a different animal i think) i'll have to dig deeper maybe

In this here book It says there was only one kind of 400 for the road runners In 1972.And It was an HP.

It also says:

"All high-performance engines will be painted orange."