When running custom exhaust, like stainless, what is done about the exhaust fuel heating pipe? My engine has one side rusted out you see. Is it wise to just cut these off? Or find another complete tube?

easy enough to just chuck on a new or good second hand manifold on
even in warmer climates the car will still run better around town and get better economy with them hooked up right

People running custom exhausts are usually running duals and the pre heat ia not required

For smooth running with a single set up a propper pre heat is better

yes it will still stay single carb. so with custom exhaust, its better to leave the heatpipes there, even if they are not hooked up. say with a stainless sidewinder setup, doesn't have the flanges to bolt on the heatpipes?

nah they dont have preheat flanges,

99% of people installing a sidewinder go twin carbs or EFI so no preheat needed hence they dont come with the flanges

plus 1 5/8" is bit on the big side for a single carb engine

all your garden variety 4 into 1 headers usually have them though, its only fully merged that dont

When running custom exhaust like sidewinders, ceramic coated or stainless, what do you do about the tinware underneath the engine? Do you just not install any of that and stop after you cover around the engine bay? The pieces im talking about are the half curved ones that run from the front pulley tinware piece to the heater boxes and back towards the flywheel.

Also when the engine has thermostat, without this tin would it affect the engines heating and cooling? example is on a twin carb 1600 tp.

If you buy an exhaust with preheat flanges and make a plate to block this up, will it be in the way of the front pulley tinware without heater holes and without heater flanges as pictured here, http://www2.cip1.com/ProductDetails.asp?ProductCode=ACC-C10-6217&CartID=15  or do they have to be cut off and the pipe welded up? Or buy a merged exhaust? what is the difference between merged and empi ceramic coated headers? I see that most merged systems are 1 5/8, would this be better for the twin carb setup?

Thanks fellas

"I see that most merged systems are 1 5/8, would this be better for the twin carb setup?"

WAY too big if you have stock valves/heads

1 3/8" is what you want for stock heads and it is really hard to get a good fully merged header in that size

Rear of the engine is the the pully end, the front is the flywheel end.

The lower 'sled' tins and heater boxes have to be in place for the thermostat to work correctly. If you dont have heater boxes a plate can be used to close off the open side.
If you have an exhaust where the sled tins wont fit dont worry about it. I have seen many VW's without them, you just wont be able to run a thermostat.

The manifold heat riser outlets on the headers dont interfere with the rear engine tin at all. The join is slightly below the tin level. The outlets usuall come blocked off (un drilled) on most aftermarket headers so no need to do any welding.You can cut them off though.

1 3/8'' is uaually the recommended header pipe size for stock heads. The most popular system out there in aftermarket land would have to be a simple 4 into 1 single quiet pack system. It also seems like one of the better performers.

Ceramic coating is a more durable finish. It resists the urge to rust like standard painted steel .
Stainless steel being even better.