Any one have any experience with cast iron or aluminum bowtie heads on the street, I'm considering picking up a pair to use them with my '69 DZ intake and 4053 carb setup but I'm not sure how the choke would (or wouldn't) work without the heat/water passage to the bimetal coil on the intake.
Any suggestions or comments?

Also what are differences between the different "phases" of bowtie heads available?

I can't say about the choke but I ran a pair on a 355 way back in the early 80's and they performed well enough to make my full weight 68 camaro run 12 teens on street tires and through the mufflers with too little gear or converter for the camshaft I was running.

I really don't know much about them. That was the first and last small block I built (I'm working on a 383 now though). Just picked them up on a recommendation from my machinest. Not sure about the different phases either.

Sorry, not much help, I just thought they worked well.

Well not many replies to this type of post, everyone likes original I guess?? I've since decided to go with a 034 bowtie casting, I'll let you all know how it turns out!!