I have a gen 4 - 454 and I have a Dart intake on it. The stock intake had the bypass hose from the water pump to the intake on it. The Dart does not allow for the horizontal fitting to hook up this hose. There are 2 ports on either side of the thermostat housing, but these would be vertical fittings. What is everyone's experience in eliminating this hose, or should you run a hose to one of the other ports?

thanks

drill and tap the dart intake in the same spot the stock one was,it dumps the extra water that the block cant take..

That hose is there so water will circulate in motor until thermostat opens .I have seen spacer blocks that raise the thermostat housing with a drilled /tapped riser if you don't want to drill intake .As long as "bypass" hose is under thermostat it'll work. You should use the bypass hose .JMO

Drill and tap a riser so the intake stays untouched.

Thanks guys. I will look for a riser to drill/tap. Seems like the best option here. I found a 90* fitting that would go into the port to the side of the thermostat housing. Would this option work? This port drops into the intake below the thermostat housing.

Since that hole is "under" the thermostat,it would work .It would look like hell though .Just got off Summit Racing looking at water neck spacers .Here's one,
http://www.summitracing.com/parts/ctr-80-116/overview/
...they have others

This is one of those questions that has more than one answer. In an automotive application, or actually anything that has the tstat directly in the manifold it is there to allow water to circulate before the Tstat opens.

In a most stock marine applications the tstat is actually up in the thermostat housing. So water is circulating through the block all the time. When the tstat opens it is actually allowing hot water from the block "circut" to leave. The block circut is pressurized by the sea pump, but just loops around & around until the tstat lets some hot water out, then the cold water replaces it.

Am I making sense? It took me a while to figure this out back in the day.

Now that you say that and I think about it, you are damn sure right ..No bypass hose necessary, unless thermostat sits in intake. thanks for the lesson

This applies to my build - I am using the Dart single plane intake, just like the HP500 Carb engines use. No provisions for bypass hose. I was planning to use the newer style T-stat housing to eliminate the two extra hoses that the octopus-looking old style T-stat housing uses. Can I run this T-stat with this manifold, or will I need to drill and tap for bypass or add a spacer as described earlier? I looked at a lot of pictures of HP500's, and most of them appear to be using the early style T-stat housing if they weren't using a crossover.

Thanks.

If you have the later model 4 hose t-stat housing, it takes care of the recirculation - amongst other things - for you.