Heat Riser Mod?

[Flmarine71]

Original 1978 350 on k5 Blazer
Does it appear from these pics that the PO got rid of operational heat riser? If so, could I replace air cleaner with aftermarket one and valve cover breather (that doesn't connect to air cleaner) and get rid of the riser tube altogether?
I'm in central Florida so doesn't get real cold. The PO hacked up the stock air cleaner pretty good to fit on edelbrock carb so I wanted to replace. The sensor has been removed from air cleaner.

From reading other threads it seems purpose is to heat up carb when cold but someone also mentioned removing could contribute to fuel percolation in carb due to lack of air flow? Any other reason to keep? Thanks.

[geezer#99]

Sure you can take the tube and the connector on the manifold off and install a different air cleaner.
You'll still need a breather on one cover and a pcv on the other cover.
THe heat riser diverted exhaust heat under the intake plenum below the carb to help warm ups. With no heat riser you won't get much (if any) heat there but you might want a heat spacer under the carb to keep it cool during the hotter temps of summer. The fuel can boil out of the eddy carbs under high heat conditions.

[AcampoDave]

I removed a lot more than the tube on mine http://67-72chevytrucks.com/vboard/s...d.php?t=622936

[Ironangel]

Yeah, you dont need any of that stuff especially in Florida. What's important is maintaining the "positive crankcase ventilation" like Geezer99 indicated. One valve cover should support the PCV valve piped to the base of the carb, the opposing valve cover needs a "vented cap" similar to the chrome cap in this pic. You can still use that cool chrome breather assembly to, or sell it to me!

[Flmarine71]

Originally Posted by AcampoDave

I removed a lot more than the tube on mine http://67-72chevytrucks.com/vboard/s...d.php?t=622936

That is cool

[Flmarine71]

Originally Posted by geezer#99

Sure you can take the tube and the connector on the manifold off and install a different air cleaner.
You'll still need a breather on one cover and a pcv on the other cover.
THe heat riser diverted exhaust heat under the intake plenum below the carb to help warm ups. With no heat riser you won't get much (if any) heat there but you might want a heat spacer under the carb to keep it cool during the hotter temps of summer. The fuel can boil out of the eddy carbs under high heat conditions.

Thanks Geezer.