Also BBC 840 head flow data
 

I have a stock 1969 427BBC. The heads are stock Hi-Perf GM1T,#3919840,square port,2.19int and 1.72ex,closed chamber,106.8 combustion chamber.
They have never been ported and I want to keep them that way.Does anyone know what they would flow from the factory,int and ext??Have you seen any tests done on them? I can't find any info. on these heads either.

ive heard perhaps the best stock iron bbc heads made for racing is the 990 head then the 840...not sure but id say you have a head worth keeping for a good street strip head good luk

Ya I will be keeping these,I have them on my Blown Pro Street 57' thats in Show Off. But I'm very curious what they flow.

Hello
There are quite a few BBC heads on here

http://users.erols.com/srweiss/tablehdc.htm#BBChevy