It's so simple that one of the biggest F series SOHC N/A guy's, when starting it, never finished it. (sohcarchangel from ad.com)
But he had more serious issues like you mentioned.
I think it's a good idea to go with the adapter plate, will allow you to take less material away from the intake ports at the head itself.
Yes. I'll overlay the F23 gasket on the plate to drill the mounting holes, then drill out a rough outline for the ports and knock those out. I'll probably use a file to do the final shaping of the ports. After that i can mount the H23 gasket to the reverse side of the plate, and again use the file to flare the port holes out to match the H23 gasket. My head is already ported and polished, so I intend to bolt the adapter plate to the head and use some sand paper/flapper wheels to match the porting.
Once that's done I'll send out the H23 IM to my guy to be polished and port matched to the throttle body, and we'll go from there. I need to work out all the details about coolant lines, and blocking off the plethora of vacuum ports on the H23 IM.
so far so good on this new gasket. right now i have bigger fish to fry
you are gonna run the full IAB setup?
So you're in the same boat as most people, having the huge runners slamming into the small ports, right?
Yes, I'll be running the IABs as they were designed. I've seen several dynos comparing the manifold with no spacers, multiple spacers, spacers with IABs, and IAB's removed completely, and I don't see any need to remove them, especially how our motors like to breathe down low. The goal here is to increase torque throughout the entire rpm range.
The IM and giant throttle body (12mm larger than stock) have provided HUGE improvements in throttle response for anyone who's used them. My goal is to see a minimum 5-8wtq increase across the lower half of the power and, and 8-10wtq across the upper half after tuning.
I'm not sure how those numbers will play out, considering the head work and new cam will be installed along with the IM to save me some labor. I've got hopes of an additional ~30+whp with those mods considering how well the car has responded so far. Once the stock exhaust is replaced and I get a better header, I'd like to see 200whp.