In the process of doing heads on my 98 vette. It looks like the two rear passages on the block deck (where the heads mate) were filled with (epoxy/ block filler). Any idea why?
The shape of these passages look identical to the front where to stream tubes bolt in.

Will this interfere with a 243 head install.

 

If it is the steam passage holes, it sounds like it might be that someone got rid of the ls1 style tubes and went with the updated style. I believe they only use a single cross over instead of all of the points. Whoever did it probably didn't want to buy plugs so they epoxied it shut.

 

I had thought of that however it had the full crossover when I pulled it?? Anyone think it'll hurt keeping it plugged?

 

Pics of the area?