Has anyone replaced these exhaust manifolds with an aftermarket; the ones currently on boat are not available; getting hot on one side; research says they can be replaced with any 454 manifold; may have to change up exhaust connections to work; thanks
Is there info on this boat in our archives? Coolant flow diagram maybe?
I replaced mine with the Barr CHVA-1-84s. I went with those because I could plumb the outputs from the thermostat housing to the front of the manifolds and the outputs from the pressure release valves to the back of the manifolds (ended up using same hoses). You can go with either the 3 inch or 4 inch risers - but will have to step down or up the the 3.5 inch collector pipe.
The other option I have seen is the Mercruiser type - only one inlet plumbed to the bottom - so could plumb the PRVs outlets to the bottom and the thermostat housing to the risers (using appropriate gasket). The Mercruiser type is just a little taller - so another consideration for deck height.
Note: this is for the raw water cooling arrangement.
Ok; thanks; I was thinking of taking the approach to just replaced all 4, being that boat is 40 years old; want best chance of longevity with engines; what Oil weight are you using; calls for 10w- 30
I use Rotella T4 15W- 40 because of the high zddp concentration. They make a 10w30 version too (a little harder to find) - but I have been getting good pressure with the 15w40.
The guys at CD's Engine recommended this stuff for older engines. They specialize in older high-performance engines, not sure anyone knows more. They do make other weights.
Thanks; I bought a case of Shaffers Oil; 10w-30; buddy had Scott White build some custom engines for his performance boat and recommended this stuff; supposed to be high quality oil; should be for $10 a quart…