Coolant line sizing?

[pb]

What size coolant lines are people using. I believe I have 3/4' from pump to tee and then 5/8' every else. Would 3/4" all the way around be more beneficial than the 5/8" I am in the process of ordering -AN fittings and hose and want to get it correct the first time. Cooling has not been a problem. I run 150-160 all day long using the Rex thermostat housing kit. I am not sure what my block pressures are but it is a concern I have and I believe up sizing the coolant lines will increase flow to the manifolds while reducing block pressure. Am I on the right track? Advice please.
Paul

[spectras only]

pb 5/8 is plenty.

[XClutchboy725]

-8 (dash eight) would be the correct terminology for an AN Fitting I believe
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[Boater Bill]

I'm running #10 in, #10 out tee'd to #8 to header collector(s), and #8 to header water injection line(s).

[Taylorman]

I recently re-plumbed my entire cooling system. I have a Taylor jet wtih 455 and Bassetts. I used 1/2" hard stainless tubing which is equivalent to -8. This plenty large enough. In fact, I installed a ball valve to reduce the water flow to get the engine temp up to about 160-180. Hope this helps.