bob, first, I want you to know that I agree with your principle and with your intent to make the SCCA more attractive to exisiting cars built to run with other sanctions. 100% with you on these principles. STL rules are new and unfortunately seemed get the cart in front of the horse in some respects. Published rules are not often overhauled, less so when they are new.

Keeping that in mind:

if you have a Teg R setup for ITR, you may run it in STL AS IS, at the IT weight and in full compliance to the ITCS. same for an S2000 or anythign else classed in IT with a 2.0L or smaller engine (over 2.0L in STU). so those cars "may" compete in STL, just not at full STL prep levels.

Honda is the LAST manufacturer that should have an angry mob demanding non-USDM engine allowances. they have great small motors HERE (B16/17/18, K20). it's Nissan and Toyota in particular (but asian manufacturers not called "Honda" in general) who need home market support, as they sold "focus-grouped" econoboxes here before moving to "large" displacement stump pullers. Some euro and even domestic brands (ford europe, GM's Opel, etc) have simillar offerings outside of the states that would be great for STL.

As for de-tune, the intent of the phrase is to maintain the stock long block and reduce cam lift to the class limits (an accepted example is the Celica GTS 1.8L 2ZZ-GE which has over-limit valve lift). OEM compression can stay if over 11:1. the phrase does NOT mean to bolt a GSR head/intake combo to a tegR bottom end, unless you can prove that the 2 bottom ends are identical aside from compression. as delivered, they are not. even then, having "B18C5" stamped on the block of a "GSR" is illegal on its face.

I've argued in the past that anything within the displacement, CR, and lift limits of the class should be acceptable, but was refuted with arguments about rules enforcement. in reality its an attempt at artificial fiscal restraint, by keeping things "stock" you keep the development costs contained, at least on big-ticket items. imagine a field of 1.5 to 2.0L, 11:1, 0.425" valve lift 16V engines with Dart blocks and heads the likes of that seen in F1, with individual throttle bodies and all that. $100k motors before they even get bolted in. this is the "open" class concept taken to it's limits. so instead, the rules were written to make the class use stock USDM parts, which means the previous scenario is replaced by B and K series Hondas, 2ZZ Toyotas, and BP mazdas (which will do well because of the chassis they come bolted to, not the engine per se, though it's not a bad mill it's just not going to make honda level specific output).

I've just accepted that it's like hotwheels: some cars not for use will some sets.