Okay i have a lq9 longblock(317 heads currently).
I just recently purchased a new complete (valves and springs)#823 casting ls3 head for $300.
I am lookint for another #823 at the same similar price but am having difficulties. I could wait and get other part for the build or pick up a #5364 head off someone for under $300 very shortly.

Would there be an issue if i were to get this head and want to run it with my 823?

(My final goal is to get the block cammed with the L92's and carbed but im nervous about PTV clearance n other stuff but thts another subject.)

 

There is a slight size difference on the exhaust port , between the two heads. The #823 shows a slight advantage of 4-6 cfm over the #5364 in stock form . After a cnc program , there is no difference between them.

 

So get the head while its available under $300. And possible port the exhaust side.

Or wait to find another #823 which maybe above $300?

 

While technically there is no problem in running 2 different castings. It has been done many times even from the factory. IMHO if you are going to run them stock out of box no porting, I would wait and get another 823 , they flow a little better and you will have a match set.