6.6L 400 needs MORE AIR

[custom mccannix]

i am running almost completly modified engine i need to find a set of cast heads that flow better and have bigger vavles so i can go faster. i am currently running factory heads from 79 that have been decked .020 in. sitting on a block with .010 in deck i NEED MORE AIR. Also does anybody know how hard it would be to mount and install a turbo off of a 82 cummins turbo diesel 18-wheeler i have two. i know i will need one hell of a blow off vavle.

[hotrod_chevyz]

yuck your running smogger heads.If your going with a set of stock heads,get a set of pre-1972 heads,cause after 1972,pontiac heads lost a lot of power.In 1970 they put a set of heads on the judges,that promised 400HP.In 1973 all pontiac had was a set of 350HP range heads.

[hotrod_chevyz]

What cam duration do you have?

[custom mccannix]

i have been told that the 70 judge head was what i need but i can't find them. my engine trying to get air through those vavles is like trying to get a cruise ship to turn around in a kids swimming pool.

[custom mccannix]

i have a crane 282/282 duration and 484in lift energizer cam with energizer 1.65 in lift roller rockers

[custom mccannix]

i also have the energizer push rods and rhoads lifters

[hotrod_chevyz]

bigger valves dont always make your car go faster.Bigger valves are slower off the line,but make up for it later on down the road.The compression of the bigger valve heads is lower,so you sacrifice compression for flow characteristics.You will not notice a major power increase with bigger valves,unless you mill them down to get your compression back again.

[hotrod_chevyz]

I just talked my boss out of a set of 1970 GTO judge heads.they need totally reworked.But they will make a nice addition to my 400PO wich im putting in a 3200 pound car

[custom mccannix]

i plan to completly rework the heads that way i can tailor them to my motors blue printing. it is not quick off the line or in the quarter it is more adapt to long high speed runs or around a big track

[custom mccannix]

i just need to find them and it will be all good

[hotrod_chevyz]

According to my boss you cant just find a set of 70' judge heads.Thats why hes makin me pay 300 for them(wich is what i payed for my big valve SBC heads).

[hotrod_chevyz]

have you dyno'd your 400?

[custom mccannix]

I have tried e-mailing and call from east coast to west coast north to south to try to find these things at salvage parts and junk yards all over. I recently found out that my uncle has some but there on his 1970 factory grand prix

[custom mccannix]

it dynoed at 502 hp at the flywheel at 6800 rpm peak

[hotrod_chevyz]

holy crap.I have a 1972 block,with flat forged pistons,a 268 duration(if not bigger) cam,and a set of 70' gto judge heads.What kind of power do you think that will make.It has less than 30 thousand miles on the block,and im getting the heads reworked,and putting extra clutches in the 400 trans