Is my 429 CJ original?

Just got this motor, DOVE-A 4-bolt block with a 1F1 VIN, and I would like to know if it is original or a rebuild. The D0OE-R heads are still on it so I can't mic the bore but it has TRW 230-99 pistons in it????? Anyone have a clue what this TRW number is? Are they forged or cast? I pulled the pan and the numbers are on the bottoms of the pistons. The motor looks all original.....still has the correct intake and distributor on it.???? Also, instead of a date code on the heads, both say SPEC. Could not attach any photos. Thanks for reading.

Sounds like it been gone thru, They didn't come from the factory with forged pistons

Sounds like a scj to me. They came with forged trw's

From some of my info true CJ motors were cast aluminum pistons, and the SCJ motors were forged but the Part # were D10Z-6109-B for the right side and D10Z-6108-B for the left side...sounds to me like the pistons were replaced...???

FalconEh wrote:From some of my info true CJ motors were cast aluminum pistons, and the SCJ motors were forged but the Part # were D10Z-6109-B for the right side and D10Z-6108-B for the left side...sounds to me like the pistons were replaced...???

that number is on the top of the piston,his heads are still on so..........

cool40 wrote:

FalconEh wrote:From some of my info true CJ motors were cast aluminum pistons, and the SCJ motors were forged but the Part # were D10Z-6109-B for the right side and D10Z-6108-B for the left side...sounds to me like the pistons were replaced...???

that number is on the top of the piston,his heads are still on so..........

Sounds like a SCJ so ... the heads have to come of...or ?

FalconEh wrote:

cool40 wrote:

FalconEh wrote:From some of my info true CJ motors were cast aluminum pistons, and the SCJ motors were forged but the Part # were D10Z-6109-B for the right side and D10Z-6108-B for the left side...sounds to me like the pistons were replaced...???

that number is on the top of the piston,his heads are still on so..........

Sounds like a SCJ so ... the heads have to come of...or ?

the heads are still on so he can't check for the d1oz-6108.  the trw is on bottom of pistons, that I've saw anyway.

Is it a hydraulic or mechanical cam? Holley or Qjet carb?

It is a -D intake or spread bore, no carb, and I believe the lifters are hydralic. The motor is a CJ by all the info I have, but I do not know if the TRW 230-99 pistons are cast or forged or if they are original bore diameter as the heads are still on. I was hoping that someone would know the number above. My internet search has turned up nothing on this. I'd post a photo but this forum will not allow it. Thanks for your question.

230-99 is the forging blank number used by TRW when they made the pistons for Ford. YES it is a Forging using MS75 high silicon material like most TRW pistons. The engine is early enough ( because of the SPEC instead of a date code) that the forged pistons were used instead of the more common cast pistons. I have seen this on several early CJ engines. Trouble is TRW used the same forging number for the replacement .030 over flat top pistons.

Hi gt350hr,
Thanks for this important bit of information! Do you know if there is an old TRW data sheet or cross ref. guide I could locate. If I sent you an image of the piston would it help you confirm it as a forged piston? So, if the motor has been rebuilt, it could have had cast pistons and it was rebuilt using forged. It is my understanding TRW stopped making pistons many years ago, but? The motor assembly date is 1/14/1971 and it was in a Mustang. THANKS!

If the piston skirt has the "figure 8" look to it it's a forged piston.

If it has the forging number it's a forged piston. You would see it right away if it's a casting.

cool40 wrote:If the piston skirt has the "figure 8" look to it it's a forged piston.

Yes, the pistons have the figure 8....Thanks.

You are also correct that it could have been rebuilt and received those pistons. Again that same forging was used for .030 over replacements. The only way to tell is pull a head and measure the bore or find a part number.

Pans off, cant you reach up to the cylinder with a snap gauge and get a good idea what the bore is? Don't need to know to the tenth but knowing 20-30 over will tell you a bunch.

paperman wrote:Pans off, cant you reach up to the cylinder with a snap gauge and get a good idea what the bore is?  Don't need to know to the tenth but knowing 20-30 over will tell you a bunch.

Yea, I think I can get a caliper in there. Will try it today. Thanks.