Extrude Honing TPI runners

[Mark Romans]

Hi all. I am tring to decide what runners to use on my 87 TPI 350. I
would like to use the Lingefelter box but at $600.00 just for the
runners and plenum, Pass. Next thing that looks good is the SLP siamesed
runners. GM PN 12341415. They are available for $270.00 from summit,
almost $100.00 less than gm dealer cost. The thing is they appear to be
the same tubing diameter as the stock runners (1.470") The tpis large
tube runners are 1.660".  

I can't find anything anymore on extrude honing. (Should I have the SLP
runners extruded honed to 1.660"?) What's everyones experience on this?
Also bases, what's everyones experience. Edelbrocks base is the least
expensive and shows more material for porting and raising the port too. 

I am having a new set of 88 vette heads ported and 2.0 1.565 valves
installed. I bought a new lt4 "Hot" cam from gm performance parts. 218
deg int, 228 deg exh at .050. .525 lift with 1.6 rockers. Mastertune is
allowing eprom modifications to compensate.  Thanks. Mark.