Porting GM "193" swirl castings

[Ron Slabaugh]

Mike:

Do you have any experience working with the "193" GM castings found on 1987-1995 TBI 350s? These heads have a really large lump in the intake bowl to induce swirl. Internet data reports flow is limited to about 170 cfm intake, 140 exhaust.

I have these heads on the L05 350 in my '95 K1500. I'm not looking to set any records here. I want to retain the stock 4000 rpm redline. I'm looking for more torque in the 2,500 to 3,500 rpm range. I think getting the heads to flow above 210 cfm, with a larger cam and EPROM programming would do the trick.

Any ideas what your stage 1 bowl work would do for these heads?

[Mike Stark]

I've done a few sets of those heads. They seem to work pretty well in a case like yours (small cubes and low RPM). Bowl work and a good valve job will net you aound 195 to 200 cfm. That will be a nice 35 HP gain or so over stock. I have these heads on a customers truck that makes great torque and get pretty good mileage too.

[Ron Slabaugh]

Thank you Mike