[70FirebirdFormula]

What is their value (What should i expect to pay), and are they as good as round port heads in the motor is tuned correctly ?

[70FirebirdFormula]

What is their value (What should i expect to pay), and are they as good as round port heads in the motor is tuned correctly ?

[racerboy]

12s are going to cost you around $500. There's actaully a rebuilt set on eBay right now for $700
Ram Air III heads

The reason is that restorers of 1970 RA III TAs, GTOs, and Judges are looking for the correct numbers. I know because I have a set of 13s on my 1970 Trans Am, and while they are probably just as good as the 12s from a performance perspective, they aren't correct. So I spent the money for a set of 12s (with matching intake).

As for the comparison with the round-ports, the two motors really are two different animals. It all depends on what you are looking for. You can get a D-port head to run just as well on a street motor as a round-port (I’m not including the Edelbrock or KRE heads, only the cast iron round-ports). To get the most out of the 614s (1970 RA IV heads) you are going to need more cam and more gearing which could ultimately detract from streetability. Not to mention the cost of round-ports.

Like I said, I have a matching RA III top end for my 70 TA, but I also have a complete 1970 RA IV top end. If I find a RA IV block (WW casting) before I find a RA III block (WS casting), I will likely put the round-port motor in the car. Not because the RA IV will be faster, but because I just happen to love the look of a round-port motor.

I’m sure that there are going to be others who tell you that the round port is the way to go, but from a practical perspective. I just think it’s easier to get a set of good D-ports (12, 13, 16, 48) and get some port work done, then spending gobs of money on cast iron round ports. If ultimate performance is truly your goal, then the aluminum heads are what you should be looking at.

Just my 2 cents.