Valley pan 440.

[T5 copper]

Do you need to add gaskets to the valley pan I hear yes and no.

 

[diesel_lv]

Typically the gaskets are 0.020" thick each, 1 against head, 1 against manifold, sandwiching pan between. It depends on the fit of the manifold to the heads. Some don't need any, some 1 and some both. I used 6 pieces of solder, 1 on each corner and 1 in the middle of both sides. Torqued down manifold to heads w no gaskets or pan. Unbolted and the measured the squished solder to determine my gasket stack. And if my manifold needed milling.

 

[RemCharger]

The stock pan was designed to be used on its own. That's why there is those "crush ribs" stamped into it.
But as Diesel said, there can be instances where extra is needed.
With everything cleaned up, first try the manifold on to see if you can rock it, or an gaps in the corners you can stick a feeler Guage in.
Or the solder trick.

 

[T5 copper]

Thanks for the info.

 

[zyzzyx]

To be clearer, You don't know if the heads or the intake manifold was ever milled. What I do is bolt the
intake manifold to one head only with no gaskets at all. Measure the gap that you have between the intake
and the other head. this gap will tell you what you need, if anything. Easy-Peasy!