# 421 Badging



## VettenGoat (Jun 19, 2007)

I suppose it varied from dealer to dealer, or perhaps Royal set the precedent, but does anyone know if cars with dealer installed 421s had any badging done? (i.e. valve cover decals or 421 emblems). 

I've been told of 421 on running boards, seen a 421 badge mounted next to the fan shield, and seen 421/425hp valve cover decals for sale. I'm sure its ad hoc, but was there a standard for badging?

Mike

(No Rukee you can't have my 421!!!)


----------



## geeteeohguy (Feb 2, 2008)

I know of no GTO's in '64 or '65 that had dealer installed 421 engines, except for the single red '64 Motor Trend test car. I think that was a factory job. Do you have any documentation that this was ever done? Just curious. If I had a 421 in my own '65, I'd probably not install the emblems....if I did, I might put a single 421 emblem on the deck lid, opposite the GTO emblem..Gotta be subtle!


----------



## 65GTO421HO (Mar 1, 2009)

Mike - I have a '65 GTO with a dealer-installed 421HO motor. There are no emblems or decals anywhere noting it as such. You could use the license plate, I suppose!

Carl


----------



## geeteeohguy (Feb 2, 2008)

Mike, do you have the dealer's invoice? It would be great if we could document some of these early (pre-Motion/Baldwin/Royal) engine upgrades. Do you know what dealer did the swap? Thanks for any additional info. As I said previously, I'm aware of 428 swaps by Royal Pontiac, etc. in '67--'69, but I was unaware of any earlier upgrades.


----------



## avman (Nov 25, 2011)

*Indentity crisis..*

Hello! My wife has wanted a '65 GTO for a few years, and I am not going to argue against the one we found. I used data/info on this forum to discover that it has, IN FACT, a 421 motor in it. The engine block code is: K 10 5 and the other number is 9782611. *HERE is where I need some help: I cant find out WHAT KIND of 421 block it is, i.e.: tripower, 4 bolt main, etc.* There hasn't yet been found the "2 letter code" that comes on the block? somewhere? to designate what kind of 421 it is. The car was an original 389 4bbl.
If you can help me determine more info on further identifying what kind of 421 it is, and point me to some posts detailing what advantages/disadvantages there are to a 421 tripower motor, I would appreciate it. Regardless, a deal has been struck, and should be concluded tomorrow.
Thanks!! (I'm a MOPAR guy, but the car is for my wife...ahem...) My dad used to race a 65 GTO at LaPlace dragway in Louisiana with the head gasket/carb jet, etc. cheater kit from Royal Pontiac. His biggest competition was other '65 GTO's! He won 1st place in his class, and has the giant trophy to prove it!


----------



## geeteeohguy (Feb 2, 2008)

Your block is a 1966 2-bolt main 421. Excellent engine. The two letter code is stamped on the front of the block, at the passenger side of the water pump/timing cover, right where the head bolts onto the block. That code will tell you what HP version it was. Your particular casting Number covers horsepower ratings of 256 all the way to 376. So you know, the only difference would be the intake and exhaust manifolds, camshafts, and heads. All of the 2 bolt blocks were the same, no matter what HP they were destined to be rated at. Being a Mopar guy, be advised that a Pontiac 421 has a 3.25" crank journal at the main's....very beefy stuff. (I think Big Block Mopar is 2.75"?)


----------



## PontiacJim (Dec 29, 2012)

A local guy where I grew up had a 421 installed in his '64 Tempest. He added the '62-'64 full size car 421 emblems having the flag just behind the headlight position like found on a 1965 Catalina 2+2. Looked factory.


----------



## avman (Nov 25, 2011)

*425 horsepower 421??*



geeteeohguy said:


> Your block is a 1966 2-bolt main 421. Excellent engine. The two letter code is stamped on the front of the block, at the passenger side of the water pump/timing cover, right where the head bolts onto the block. That code will tell you what HP version it was. Your particular casting Number covers horsepower ratings of 256 all the way to 376.


Ok. Thanks. I have searched the Internet for a 425 horsepower 421 and can't seem to find out anything, even if there is such an engine. This engine has the 421/425 horsepower decals on the valve covers, but I know that the decals can be bought for $7.99.  So does such an engine exist? If mine were one, what would I look for? Also, it is supposed to have Code#77 heads, what is the implication of that? Thanks again.


----------



## Instg8ter (Sep 28, 2010)

The only 421's with that much power were the 62-63' dual quad 421 SD in the factory race cars which were underrated at 405 HP.


----------



## avman (Nov 25, 2011)

Thanks. Darn, I was pretty excited thinking it may have 425 ponies. I have searched and discovered that the #77 heads are on all 65s and 93 octane pump gas may cause detonation issues. I will see what is being used (maybe store bought octane boost?) to help combat that while still running decent timing advance, after all, since it doesn't have 425 horsepower  , I want to get as much as reasonable out of the mill that I can without causing damage or undue wear. I forwarded the letter code location info to the dealer, so hopefully I can find out what HP level this 421 is.


----------



## avman (Nov 25, 2011)

*Here's a picture of a stamped code...*

the dealer says he took from where the letter code is supposed to be. Looks like M or 7 S, but hard to tell.


----------



## avman (Nov 25, 2011)

...meanwhile I will search for letter codes for 421s.


----------



## PontiacJim (Dec 29, 2012)

avman said:


> ...meanwhile I will search for letter codes for 421s.


OK, just for you! For the "B" body cars.

1964:
320HP - 35B,43N,38S 4BBL
350HP - 44B,49N,47S TriPower
370HP/HO - 45B,50Q,46G TriPower

1965:
338HP - WG,YH 4BBL
356HP - WH,YJ TriPower

1966:
338/350HP - WG,YZ 4BBL
356HP/HO - WH,YJ TriPower
376HP/HO - WJ,YK TriPower


----------



## avman (Nov 25, 2011)

geeteeohguy said:


> Your block is a 1966 2-bolt main 421.


Actually it is a 4 bolt main cap motor!
We had it rebuilt about 2 years ago because of a cracked crank bearing. Fortunately there was no other damage.
I replaced the 421 crank with another 421 crank I bought from Bruce Fulper and it was perfect! (Thanks Bruce) Only had to lightly polish the crank journals. I would have gone with a forged stroker crank, but budget and time were working against that. I used ARP everything everywhere including crank studs and I can assure you it is a 4 bolt cap motor. The 6777 heads had been ported and has steel roller tipped rocker arms. I added Eagle forged H beam rods, slightly dished RaceTech .035 over forged aluminum pistons for a 10:1 CR. Comp Cams roller cam and hydraulic roller lifters, billet steel sprockets and double roller timing chain, Pertronix billet aluminum distributor and Ignitor III control box. All American Carburetors has the 3 Rochesters and are restoring and rebuilding them according to the cam and other build specs I sent them from the rebuild.
I blew the spider gears in the original 8.2 OPEN rear axle, but that's ok because we've been needing a posi rear with the power the 421 cranks out. When you smoke a drag radial at the 1/8th mile mark heading to the 1320, it's time for a rear axle upgrade. Likely using a Quick Performance Ford 9" based replacement rear axle assembly. Looking at 3.70 ring and pinion, and hoping for 12.8 or better in the 1/4 mile.


----------



## PontiacJim (Dec 29, 2012)

avman said:


> Actually it is a 4 bolt main cap motor!
> We had it rebuilt about 2 years ago because of a cracked crank bearing. Fortunately there was no other damage.
> I replaced the 421 crank with another 421 crank I bought from Bruce Fulper and it was perfect! (Thanks Bruce) Only had to lightly polish the crank journals. I would have gone with a forged stroker crank, but budget and time were working against that. I used ARP everything everywhere including crank studs and I can assure you it is a 4 bolt cap motor. The 6777 heads had been ported and has steel roller tipped rocker arms. I added Eagle forged H beam rods, slightly dished RaceTech .035 over forged aluminum pistons for a 10:1 CR. Comp Cams roller cam and hydraulic roller lifters, billet steel sprockets and double roller timing chain, Pertronix billet aluminum distributor and Ignitor III control box. All American Carburetors has the 3 Rochesters and are restoring and rebuilding them according to the cam and other build specs I sent them from the rebuild.
> I blew the spider gears in the original 8.2 OPEN rear axle, but that's ok because we've been needing a posi rear with the power the 421 cranks out. When you smoke a drag radial at the 1/8th mile mark heading to the 1320, it's time for a rear axle upgrade. Likely using a Quick Time Ford 9" based replacement rear axle assembly. Looking at 3.70 ring and pinion, and hoping for 12.8 or better in the 1/4 mile.



Did you mean Quick Performance on the Ford 9" rear? Could not find anything under Quick Time other than bellhousings. :confused


----------



## avman (Nov 25, 2011)

Yes! Quick Performance! 
They were suggested as an option on the PY forum. I spoke with Quick Performance and I am good with them. There is one local Moser rep I need to call for a 2nd Moser quote to see if he can give me a better Moser quote.
Even with a number of upgrade options on the QP axle it was around $1,000 less.
Tomorrow I'm making calls on lead time. September 30 will be here before I know it!


----------

