I recently did engine swap in my 86 ram 350 van
i removed 360 4 barrel replace with 73 360 replace intake with 86 stock replace timing chain oil pump plug and wires
i used distributor from 86 and used 73 exhaust manifolds it run good enough
my question is dose this engine have harden valve seats

 

If you mean can these valves handle unleaded fuel then unless it was rebuilt since the 80's then no. Run Marvel Mystery Oil or a lead additive in the fuel to help lubricate the valves.

 

thanks for advice but i read some conflicting info on this subject some say all engines with duel plane manifolds have harden seat i do take your info to heart i hope i have
done no damage i have put 4500 miles on engine