I am looking at a motor, the heads are stamped 46 and there is an X on it at one end of the head and then it looks like GM9 at the other end and above that a small N, the block is stamped 481988(from what i can tell) and 400 is also stamped on the block. Can anyone tell what this is from the info listed? What are the performance numbers if you do have any info?
David.

It will depend on the engine code and date code on the engine block to be sure but it sounds like you have a 1969 big car 400 engine with the small valve 46 heads.

Tom

Where do i find that? There is also a number at the top of the head, i believe 2313? Guy has told me it is a 73 GTO motor.What do you all think?

The date code will be by the distributer hole at the rear of the block.

The engine code is on the front of the engine by the water pump housing.

Tom

Look on the back of the block, passenger side, just under the head. I usually look at it from under the car with a flashlight if the engine is in the car. That is the block casting #.

On the top of the block, to the driver's side of the distributor, is a cast date code. It should be three or four digits.

There should also be stampings on the front of the block, just under the passenger head which will have a (usually) two letter code like YT and a numerical code. The letter code is important.

Heads have a big pair of numbers cast in the center exhaust runners, one digit on each runner. Numbers should certainly match left and right. Some heads have different variations by date as well, even with the same casting number.

So then the # 481988 is the casting number, located passenger side near distributor,below the head.What can you tell about a motor from this? I cannot tell from the pics i was sent what the block code is or any other codes other than the heads which are stamped 46 on both sides. I guess i'll have to e-mail him back to ask him.

David

http://www.yearone.com/updatedsinglepages/Id_info/pontiacengineid/pontengid1.html

The block could be '71, '72, '73 or '74. The date code should be a letter and three numbers, not four numbers. Since there is no code Z, which could be confused with 2, I'd ask to have the date code from the distributor area read again.
http://www.yearone.com/updatedsinglepages/Id_info/pontiacengineid/pontengid2.html

The letter codes on the front will tell what car models the engine was used in.
http://www.yearone.com/updatedsinglepages/Id_info/pontiacengineid/pontengid4.html

The heads were used in '73 and '74.
http://www.yearone.com/updatedsinglepages/Id_info/pontiacengineid/pontengid5.html

http://www.yearone.com/updatedsinglepages/Id_info/pontiacengineid/pontengid3.html

Thanks Tom and Vikki! I am gonna assume That this is a 73'motor as other than the two letters on the front to denote it as otherwise, also part of the deal is a TH400 tranny(shift kit) that i can see on the tag that it has 73'stamping on it as well. I was just hoping to find a needle in a haystack as the guy only wants $600 for both and they are both rebuilt plus a set of new headers, motor has edelbrock and arp parts,the motor is minus intake.If it is the said motor,what potential might it have? I realize that this would be a lo-po motor as is. Thanks!

David

It's a Pontiac engine, it's going to be fairly torquey as the bore is larger than the stroke. The small valve #46 heads are 350 2bbl/4bbl and 400 heads with about 86cc, 1.96/1.66" valves and pressed studs, according to my chart. The compression ratio will be reasonable for pump gas on a 400, but they won't breathe as well at high rpm as some others. They have D ports. Overall it would be a decent pump gas driver, not a screamer as equipped.

The price is great, and if you can hear it run you can make an informed decision. Either way, if it's someone else's rebuild, I'd go through it all before putting it in the car.

i found a great site for decodeing boocks and heads , www.wallaceracing.com just enter your info and it finds it for you, or scroll through the listings they have and find it that way

Well as much as i would like to grab the motor/tranny/header combo off this guy, the shipping would be a pain in the behind or to drive there and get it back over the border would be fun! After thinking about it,i have other things i need to pour my resources into first.Anyone interested in this motor, contact me and i will give you the contact info.The pics he sent me are nice,motor is painted,headers are new and tranny looks good.Overall the appearace of all three look very nice.I have no clue what kinda running condition they are in. He says motor/tranny have been rebuilt.They are located in Pennsylvania. Thanks for all the help on this one,i appreciate it.I have pics if you want to see without contacting the guy. Mardave68@aol.com

David