Cylinder Head ID
 

I've came across a set of BBC cylinder heads PN 19256821. They currently have 2.06 intake valves and 1.75 exhaust valves in them. (measured with a scale so might not be exact.) Small oval port with a fast burn ski ramp in the intake port and an odd-looking chamber. Anyone have any information on these castings? Best I can find is that they were made 2010-2012.
TIA

I believe they are the 7.4 Vortec heads

Interesting. My AERA Engine Rebuilders Software says they are from 2012-2019 GM and Chevrolet 8.0L 489 Crate Truck engines Engines.
https://www.jegs.com/i/Chevrolet-Per...28586/10002/-1

When you say small oval port...do you mean peanut port size? Or just a good oval port?

Most mild/med BBC perf marine engines don't need more than 2.06" intake valves.

The ski ramps help out with swirl, maybe too much.

I saw that when I searched the part # as well.
GM Gen 6 Big Block Industrial Marine 7.4L Vortec Oval Port Cylinder Head | eBay

Yeah, these are the L29 Gen 6 Vortec heads.

99cc chamber.

They have a reasonable HP potential.

They would benefit from cutting down the quench pad on the Exh valve size. Increase chamber CCs, but lets the exh flow better.

Here are pics of the heads being discussed. I think they'll be a worthwhile winter project to replace my peanut ports. I'll put them on the flow bench as is and document the progress. Not sure if I'll increase valve sizes or not. I'll see what the heads on the engine have for valves. If they're bigger I may just do a valve and spring swap along with moderate porting.


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