Howdy, new to the site. 30 years ago(!) I had a ex-SCCA RX2 that was converted back to street use with a bridgeport motor. I tore it down and rebuilt it several times with dyno castoffs from Racing Beat. They were very accomodating to a high schoold kid with no money (may I pay you next wednesday for bridgeport irons today?) One time when I was paying my tab there my POS nova popped out of gear and almost took out their recently crowned record breaking LSD car plus the brand new RX7 that the factory had given them for breaking the record. Anyway, I've obtained a 90 NA convertible with a blown motor (ported) and a ton of spares. I tore the motor down and 2 of the 3 irons have places where the thin iron between the outer seal and water passages has been eroded. My guess is that this thing got smoking hot a few times. Among the spares is a pair of housings and a front & rear irons. I need the middle iron for a 6-port S5 NA motor. It looks like I could use an S4 iron with a blockoff plate for the EGR. The outer irons have a sleeve that appears to block off the port. Can that sleeve be removed for extra flow? If so, would you need to do any port work to the middle iron to compensate?

I'm too new to PM or post in any of the adverts so I need a little help with parts.

Thanks for your time.