Pre heat duct tbi

[Xxl2]

I have a 91 4.3 the pre heat duct for the air cleaner is gone. Is it really necessary to have? Could i swap the 4.3 intake for like a 5.7 ?

 

[Wildblue19]

If you live in really cold climates it may help, otherwise not really needed in a more temperate climate

 

[Schurkey]

Any time you're in a situation with high humidity where the weather is ~32--50 degrees F; mostly around 40F--45F and raining, that heat duct is essential to prevent carb throttle-body icing. The rest of the time, it's merely "helpful" to have.

Be sure the air door in the snorkel works properly--selecting hot air when cold, selecting cold (ambient) air when the engine is fully warm. Not uncommon for them to be partially hot--mostly cold in summer, and partially cold, mostly hot in winter. They are intended to keep the intake air reasonably warm year around.

Most folks around here would love to have a 4.3 snorkel and duct assembly instead of the V-8 system, since the 4.3 ductwork is--apparently--less restrictive.

 

[GoToGuy]

If it's just the foil tube from manifold , you get new foil at any parts place in a box. Just need your tube ID.