# 455 Question



## Josh.AZ.GTO (Jul 11, 2009)

If the engine was originally set up from factory as an automatic.....will it directly bolt up to a muncie 4 spd? My car was originally a 4spd and was converted over to an automatic. I want to change it back, and found a year matching 455 block for sale that was from an automatic car. 

I've always assumed they could easily accept either or..but I'm not sure and that is why I'm asking.

Thank you in advance.

JR


----------



## BearGFR (Aug 25, 2008)

Josh.AZ.GTO said:


> If the engine was originally set up from factory as an automatic.....will it directly bolt up to a muncie 4 spd? My car was originally a 4spd and was converted over to an automatic. I want to change it back, and found a year matching 455 block for sale that was from an automatic car.
> 
> I've always assumed they could easily accept either or..but I'm not sure and that is why I'm asking.
> 
> ...


The bolt pattern on the rear of the engine is the same, so no worries there. I've heard, but never personally verified, that occasionally you might find a block from an automatic car that doesn't have the driver's side "socket" for the clutch Z-bar drilled, and also - on occasion - you might find a crank that isn't drilled to accept the transmission pilot bushing. Both of those are at least worth checking before you plunk down your cash.

Bear


----------



## Eric Animal (Oct 28, 2007)

I've heard the same about the crank/pilot bushing, never seen one though......I personally would run a hydraulic clutch, you won't need the "clutch linkage" then... E


----------



## Josh.AZ.GTO (Jul 11, 2009)

The block is a code XF and block only. If this helps for any more information.


----------



## BearGFR (Aug 25, 2008)

Josh.AZ.GTO said:


> The block is a code XF and block only. If this helps for any more information.


Gotta start with the date code first - that's 4 characters near the distributor hole, on top of the rear of the block. Until you know what year it is, that XF doesn't tell you much.

Bear


----------



## Josh.AZ.GTO (Jul 11, 2009)

XF 0258327.

Does this help Bear?


----------



## BearGFR (Aug 25, 2008)

Josh.AZ.GTO said:


> XF 0258327.
> 
> Does this help Bear?


No sir, that's a sequence number used during engine manufacture - doesn't really relate to anything.

Go here: How to identify your Pontiac engine
It has an example of where to find the date code and also shows you how to decode other things.

Bear


----------



## Josh.AZ.GTO (Jul 11, 2009)

BearGFR said:


> No sir, that's a sequence number used during engine manufacture - doesn't really relate to anything.
> 
> Go here: How to identify your Pontiac engine
> It has an example of where to find the date code and also shows you how to decode other things.
> ...


It appears to be K139 (November 13th, 1969)


----------



## BearGFR (Aug 25, 2008)

Well all-righty then. It's probably model year 1970 and therefore a 370 horse 455 out of a Grand Prix, but I 'spose also could be very late 69 and a 428 (both used XF). Go back to the same web site, see if you can get the 7-digit block casting number off the top rear passenger side - that'll clinch it. Also if it's a 455 you should find "455" cast into the side above the oil pan rail.
Next assignment is to ID the heads. You should be able to find antoher 4-character date code on the sides, similar format to the date code on the block. Then get the two (sometimes 3) character code from the tops of the center two exhaust ports.

Bear


----------



## Josh.AZ.GTO (Jul 11, 2009)

BearGFR said:


> Well all-righty then. It's probably model year 1970 and therefore a 370 horse 455 out of a Grand Prix, but I 'spose also could be very late 69 and a 428 (both used XF). Go back to the same web site, see if you can get the 7-digit block casting number off the top rear passenger side - that'll clinch it. Also if it's a 455 you should find "455" cast into the side above the oil pan rail.
> Next assignment is to ID the heads. You should be able to find antoher 4-character date code on the sides, similar format to the date code on the block. Then get the two (sometimes 3) character code from the tops of the center two exhaust ports.
> 
> Bear


Unfortunately the motor is a block only with no heads. The guy who has it did say it was from a Grand Prix though. That being said I have a Pontiac 350 (1970) carb to pan. I plan on reusing the Q-Jet. Were the heads mostly interchangeable?


----------



## likethat (Oct 5, 2007)

That is the 1970 XF 455 H.O. block for a Grand Prix. They are rare. The block alone can bring good money for the right guy. Ask him if he can get the heads or has them. They should be 64 heads. They are worth a good amount of money also. Some Pontiac guy consider that set up to be the best to buy. The drivers side of the block toward the front should say 455 vertically, or 428 if it is older. I would bet on 455.


----------



## BearGFR (Aug 25, 2008)

Josh.AZ.GTO said:


> Unfortunately the motor is a block only with no heads. The guy who has it did say it was from a Grand Prix though. That being said I have a Pontiac 350 (1970) carb to pan. I plan on reusing the Q-Jet. Were the heads mostly interchangeable?


Do you know if that XF block has 4-bolt mains and caps? It probably does.

Yes, heads are interchangeable, in that they will pretty much all bolt on. There are differences in combustion chamber shape/volume, valve sizes, and screw-in vs. pressed-in rocker studs. The better heads will have screw-in studs, 2.11" intake valves, and 1.77" exhaust valves. The problem with using heads from a 350 would be that on a 428 or 455 (got that casting number yet?) your compression ratio would be way too high for street/pump gas unless you took some pretty extreme measures to lower it. Getting the date codes and casting codes from the heads will help positively id them.

QJets varied quite a bit too. There should be a number stamped into the side of it that begins with either "70.." or "170.." that'll help id that one. Get a copy of Cliff Ruggles' book, How to Rebuild and Modify Rochester Quadrajet Carburetors, avaialable on his web site and also through most major book stores. That'll walk you through id'ing the carb and also tell you what and how to recalibrate it for the bigger motor. The idle, transition, and main metering circuits will definitely need some attention to make the jump from a 350 to a 455.

If you'd prefer to have your motor "built" by someone else, the best in the business is on this same forum under the name "Mr. PBody" - Jim Lehart of Central Virgina Machine Service. He helped me plan my 461 and also supplied and balanced the rotating assembly, valve train, and other miscellaneous pieces.

Bear


----------



## Josh.AZ.GTO (Jul 11, 2009)

BearGFR said:


> Do you know if that XF block has 4-bolt mains and caps? It probably does.
> 
> Yes, heads are interchangeable, in that they will pretty much all bolt on. There are differences in combustion chamber shape/volume, valve sizes, and screw-in vs. pressed-in rocker studs. The better heads will have screw-in studs, 2.11" intake valves, and 1.77" exhaust valves. The problem with using heads from a 350 would be that on a 428 or 455 (got that casting number yet?) your compression ratio would be way too high for street/pump gas unless you took some pretty extreme measures to lower it. Getting the date codes and casting codes from the heads will help positively id them.
> 
> ...


Block casting No. 9799140, came with #64 heads but does not have them anymore.


----------

