340X heads vs late model LA heads vs Magnum.

70aarcuda said

the 318 heads have small ports and will choke the 340 ...

magnum heads do offer better flow put the close chamber heads could be a problem with a 340 if the 340 has positive deck height pistons...you will need thicker head gaskets which will negate the quench...

probably need to tear the end down and see what you got before making any big decisions...especially if you are on a budget...

if the 340x heads ported have they been on a flow bench?....new 11/32 valves...2.055 and 1.625 valves with the bowl work done might be your best bet....

eddy air gap is a good choice...

Click to expand...

340dartley just some food for thought. IF you need new guides,Valves,springs?,harden seats?.....Porting????? it may be cost effective to just buy some RHS Heads........

If you port them more, the head could crack in side the intake port(all your $$$$ wasted.

The RHS will probably flow more air, but you won't know that until you get yours flow test done. aka more money with "0" gain.

I'm not saying that 70aarcuda is wrong, in fact i thing it's a good idea! Just get a good Quote before you jump in with both feet.