well i rigged up a test fitting today .
the 3/8" pipe thread port in the front of the vortec intake from edelbrock is for a bypass hose port if your using a vortec pump and i am NOT .
so i took the 1/2" pipe to 3/4" barb fitting out of the water pump today and swapped it for a 1/2" pipe to 5/8" barb fitting . then i used a 3/8" pipe to 3/8" brass compression fitting 90* to go in the intake bypass port hole . then a 5/8" molded 90* bypass hose was used from napa #7296 to link them together .
i did find a fitting on line thats going to make the hook up a lot better and more snug a fit on the hose for the intake end and help the bend over angle of the hose to keep it from closing off . reason is the water pump port is angled up 45* ish and over to the pass side . the intake manifold port is straight out the front and to the left of the water pump port location .
here is a few pics of the hose and fitting i will order and use when i do some other swapping around soon and have the system drained .
https://www.ebay.com/itm/5-8-HOSE-B....l/191761802124
the hose size or fitting size do not matter to much as the intake has a smaller hole back in before it goes in to the crossover just below the t-stat location . so it only pulls the fluid volume it needs and its the same basic size as the older blocks and water pumps bypass port on the mounting face at the block on the pass side . here is the rpm edelbrock vortec pattern intake front drawing view . note the pipe thread port location bigger hose and closer to center . the smaller hole is for mounting brackets to it .
i warmed the truck up to mid 140* range and capped the rad off / topped off the over flow bottle and took her for a road test for almost 20 min driving . 30-50mph ranges and not 1 burp / girggle / sound from the system . got the tinyest wiff of coolant smell early on was all and nothing after the fact . temp gauge was a lot more steady and didn't do as big a swings from open to cold . so cross my fingers i think its 99% solved but not sure until more road time .