cast iron heads for intercooled twin turbo setup

[Peter Gaw]

I used to have a GN and decided to abuse my 69 a bit.

Just ordered a new intercooled twin turbo kit for my Chevelle.
It's an old 327 ss engine 30 over, steel crank etc.

I have been running an old draw thru system and have efi installed and alky water injection. Wasn't able to get more than 29 degrees total advance before there was too much pinging. Compression is approx 8.5 to one and an using 76cc chamber ported heads instead of the camel humps of course. Also running alky water injection and approx 12lbs boost on the old system. Doesn't run as strong as I want or expect.

I recently installed a big 4core rad as well with 160 thermostat.

Will the intercooler be enough or do I need to shell out for aluminum heads too to keep the old girl cool enough.

[shmoov69]

I don't understand how a draw thru and efi works. Can you explain in more detail?
But, iron heads won't make much difference on keeping it cool IMO, but more of a engine timing or a radiatior water/airflow issue to me. And yes an intercooler will always help intake temps, but with the alky/water injection, that should help a bunch too.

[Peter Gaw]

I have draw thru now and efi with a throttle body from Holley. I am converting to blow thru and will just add a carb hat to the "carb like" throttle body. (sorry for the omission).
I was under the impression that aluminum heads dissipate the heat better and therefore reduce pinging and allow for more timing, boost etc.
I'm trying to not buy stuff I don't need and wondered if I can get away with iron heads by adding the intercooler which I did not have before.

[Texas Hotrod]

Any chance are you using an MSD BTM???
Is your fuel curve sufficient to boost gains???

You can't make boost w/o pulling timing and adding fuel.

[Peter Gaw]

Pulled the trigger and got aluminum heads. Edelbrock 70cc performers.
Also will be using a Victor Jr intake.
I have efi now so can set timing via computer. Used the msd 6btm but don't need it now.