I like PRH idea, enjoy it over the summer. Winter you can pull it apart and measure everything. It doesn’t cost a ton to measure what you need. I bought a bag of ten 60cc plastic syringes on Amazon for like $20. A plastic square and some grease. You can measure chamber volume. A deck bridge is $20-$30. A harbor freight dial indicator maybe $15. Measure EVERYTHING! That way you can get better answers if problems arise. In the end It takes a bunch of head work to get a cast iron head to make “significant” power. My car weighs 3445 and runs 116mph, what is that 350-380 at the wheel? X heads almost full effort, but stock pushrod location.
