do you guys think a 200cc intake port would be too big for a mild 355? im kinda worried about port velocity and bottom end.
the car is fuel injected if that makes any difference. cams slightly larger than gm's hot cam.

 

too much for a mild 355 but for a warmed up one with gears it would work try and keep port down to 180 cc if you want mild :cheers:

 

thanks cork,
the heads are actually brodix 197cc's. i wanted afr comp ported 180's w/ the vortec intake port. of course , even though AFR advertises them , they dont @#$%@ sell them and wont till the end of this year. brodix does though , with comparable flow, but their bigger ports.
i guess what i should have asked is, whats it gonna hurt to run these heads? how bad?

 

You can always use the real "Vortec" heads. Plenty of port velocity, still respectable flow. You may want a dual pattern cam becuase the exhaust ports don't flow so well. Edelbrock also make "Vortec" style heads in 170 and 200 cc port sizes.

 

actually, that was the original plan. was gonna vortec the 85. got the intake heads, and all. now, im going aluminum on the 85, but i didn't want to buy another intake..
the vortecs are going to good use though, putting them on the 80 shortly.

the brodix heads are on the way. id still like to know how bad, if at all, the bigger ports will affect bottom end?

 

They will probably reduce low rpm torque. They're likely to have sluggish throttle response below 3000-4000 rpms. Lack-luster around town performance. Good luck, ane...

RACE ON!!!

 

LS1/6 heads have considerably larger than 200 cc ports and they don't suffer from lack of low end torque.

The requirement for FI and carbureted engines are very different (and the original poster said the engine has EFI). With a carbureted engine high port velocity is necessary to achieve good fuel vaporization and distribution. On an EFI engine even fuel distribution and good atomization to promote rapid vaporization are part of the deal.

For an EFI engine, free flowing heads and a moderate cam will provide excellent torque bandwidth and very good peak power.

Duke

 

That is a great point Duke, I never thought of that.

 

I pondered the same question a couple of years ago. I went with 200's and was glad I did. Although I should taken gkulls advise and went with 215's.
:banghead:

 

:cool: :cool: