Ive been kicking around a idea in my head and have had no luck finding out if its possible. Im a little confused on exactly what is modified on the rods to allow Type-S pistons on a H23A1 rod? Is the difference in OEM rods between OBD1 and 2, or is the Type-S a one off wrist pin? Ive read you wont need rod modding if you have a A4, which makes me believe later model OBD2 engines have the same rod/wrist pin as the Type-S. Which would also mean the same for my H23aV-BT. Is it possible to have a newer rod/wrist pin fit a H23a1 pistons?

If it is not possible to go H23a1, Ive also heard of people running K series pistons on FRM. Which version rod would you need to get modified to accept those? They are forged from the factory, the K24A1's are common and 9.6:1. Then with forged rods I could be running full forged internals on a FRM block. Or would custom rods be needed to accept the K series pistons?

So let me explain my story; I currently have a H23aV blue-top and have been thinking of factory combinations to get a lower compression ratio.

Because of the wrist pin location on H23a1 piston, putting regular H22a piston on a H23A1 rod would have it stick .020" out of the hole. With 10.6:1 pistons this will now give you 11.64:1

---(Ratios according to Shawn @ RoskoRacing's H23 build FAQ Tech Blog Link: http://roskoracing.com/TechBlog/?p=27 )---

So there is a solid point in compression for the .020". My jdm blue-top rods are .020" shorter then usdm H23a1 rods because they went to normal h22 pistons and just compensated by shortening the rods.

H23a1 pistons are 9.8:1 factory with a few CC's smaller non-vtec head. So with a vtec head they are closer to 9.6:1.

If I can put the H23a1 pistons on my vtec blue-top .020" shorter rods would have the pistons sitting .020" inside the hole. Which would put me about 8.6:1 approx.

I know forged is the way to go for boost, more curious about whats possible. I also know this is the N/a section, but my Q's have nothing to do with power adders.

Thanks in advance