Hi Doc,
The Nelson head is legal in the Topeka/Wichita rules. The Texas (Dallas?) Sport Goodyear rules require a 1/4-32 glo-plug. I keep a 1/4-32 head around just in case I want to take my Sport Goodyear to Dallas. A chromed liner is OK under either rules.
Bob Oge did the chrome and head work on my engine and I've been very pleased with it. I ran my engine in stock form until it wouldn't start hot and then sent it to Bob. If you don't talk to him before, Bob should be at the F2C contest in Dallas in April.
Dave