are cylinder heads same with tall deck and standart deck?
9.800 and 10.200

Yes, only the intake is different.

. . .and pushrod length. You may have to change your distributor also.

Chris

related topic,,building my next motors(in the distant future).Aside from the expense of the intakes and dist?,why build a 540 when I could build a 598? What are the tradeoffs? Seems you can buy a 598 short block for the same as a 598. Is this right? What decides the Dist. change? How much $ to change it and are some intakes made so this is not needed?

You can get longer rods in a tall deck. This reduces rod angularity and reduces piston wear caused by thrust on the cylinder wall. It also allows you to use longer pistons which tend to sit more square in the cylinder bore which promotes ring seal. The longest stroke I have seen in a short deck is 4.375. The longest stroke I've seen in a tall deck is 4.750.

Be aware that the block is tall enough to make your exhaust not line up with the existing holes in the transom if you are changing blocks.

the dist wont engage the oil pump drive nor will it line up with the cam gear. you can machine the collar off you dist and buy a slip collar thta msd sells. they use the slip collar on the better dist the they sell so you can run it in a tall deck. i bought a pair of msd dist. and bought a pair of collars so they will work on a tall deck. i have seen people machine the bottom half of the collar off and machine the intake where the dist mount to make a short deck dist work. but you still won't have full engagement to the oil pump drive.

Some intakes have the dist. pad machined, but always check the dist. gear mesh. MSD dists. have a movable collar.