There is nothing extra special but they are very long, and two different lengths. because of the length you are going to want to buy a really good name brand pushrod with some wall thickness. With the Indy rockers you will want no oil holes in the pushrod cups to keep an oil "well" at the rocker ball/cup interface. Its going to be small details like this that will make a difference. They will be more money than you think.....
I would also order the cam with a full groove journal, depending on what block you have so that the heads will have full time oil to the rockers. This will be an option so you would have to specify. Some block take oil directly from the lifter galley and bypass the cam journal so it would be wise to determine what block you have. Also would use Indy's oil restrictors in the heads to meter the oil flow. You would have to check the heads to see if they are installed already or not.
AG.

Yes I read that in your first post.

The question was, did you measure this yourself and confirm it or is that what you were told.

When you have stuff like that which is unknown to you I'd start out by running it on a dyno. Get yourself some baseline numbers and then figure it out from there. With the engine on the dyno you can check for leaks, run a compression check, watch each cylinder EGT during a pull, etc. Engines like that are grenades if they haven't been put together properly and it is a lot of work (and a big hassle) to put it in a car only to find out that there is a pan leak, or a rear main leak, or the thrust bearing is pounded out, or some other such problem.

That's a good idea but part of where I was going with my question is what does it have for a ring pack?

If the goal is to not disassemble the short block but it has very low tension rings are you ok with running a vacuum pump, as it seems to have had one previously based on the pulley/mandrel.

If deemed necessary to reduce compression I would just change the pistons or possibly machine some dome off the current pistons if that's an option.

Aside from the pushrod issue mentioned I would think it would be unfavorable to open up piston to chamber distance (I check with solder) and then you're going to need thicker intake gaskets which may not hold as well.

the compression ratios previously listen in this post is measured by a well know and professional engine builder. I got all the information from the engine builder and when I run them trough various compression calculators I get the same results.

the compression ratios previously listen in this post is measured by a well know and professional engine builder. I got all the information from the engine builder and when I run them trough various compression calculators I get the same results.

This engine will for sure be run on the dyno before it will be installed in the car.

Where I want with my post to start with is to get a confirmation that lowering the compression with a gasket change from 0.045" to 0.092" is acceptable, would be much appreciated if you could share your thoughts on that.

Here is the spec sheet on the pistons that in the engine now:

Everything may be dead on. And.... may be not.

I like- trust but verify.

Sure the math adds up, to a point. But if I recall correctly the builder didn't know what cam was in it. But knows all other details?

Again, wouldn't be surprised if it measured out to what you were told. Also, wouldn't be surprised if it didn't.

You're free to do as you wish of course. Just saying, if that was my engine, I would measure everything myself before I made any decisions to change it.

What rod length do you have in the engine ? I did a quick compression calculations making a few assumptions and don't come up with anything close to 13:1..

Deck Height 10.725
Head Volume 166
Gasket Bore 4.59
Gasket THK. 0.051
Stroke 4.15
Bore 4.40
Rod Length 7.10
Gasket volume 13.83
Piston Volume -92.4
Piston Comp. Height 1.500
Piston below deck(+) 0.050
Volume @ BDC 1133.49
Volume @ TDC 99.88
Compression 11.348

Did Indy build the engine ?

If so hit em em for the build info !

I had a little more time to play with the numbers. I am still making assumptions but I brought the deck height down to "0" but still not getting 13:1 but close.....
AG.

Deck Height 10.675
Head Volume 166
Gasket Bore 4.59
Gasket THK. 0.051
Stroke 4.15
Bore 4.40
Rod Length 7.10
Gasket volume 13.83
Piston Volume -92.4
Piston Comp. Height 1.500
Piston below deck(+) 0.000
Volume @ BDC 1121.04
Volume @ TDC 87.43
Compression 12.8

Rod lenght of 7.10”. Block is milled 0.025” so the deck height is 10.70”

Ok, with those numbers I get 12:1.. You could try and call JE with your piston info and maybe they can tell you if there is enough material to reconfigure the dome but you will still be in it for a rebalance ...
AG.

Deck Height 10.7
Head Volume 166
Gasket Bore 4.59
Gasket THK. 0.051
Stroke 4.15
Bore 4.40
Rod Length 7.10
Gasket volume 13.83
Piston Volume -92.4
Piston Comp. Height 1.500
Piston below deck(+) 0.025
Volume @ BDC 1127.27
Volume @ TDC 93.66
Compression 12.0

x1000