under drive pullies

[dad]

would it hurt to leave the under drive pullies on with an eaton swap

[SC Cheesehead]

would it hurt to leave the under drive pullies on with an eaton swap

Yes.
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[MOTOWN]

would it hurt to leave the under drive pullies on with an eaton swap

It would throw the boost way off:mad2:, pulley size is what dictates boost psi on a S/C car.

[RF Overlord]

Would it HURT anything? No. But why would you want to? As they ^^^ said, you'll have lower boost and there's no other advantage.

[dad]

thk u all i wasnt sure if i had to swap them out if jt would make a difference

[Vortech347]

If its an under drive crank and the blower has its own pulley and belt. No! If its a single serpentine belt. Yes! If I remember correctly eaton swaps use a separate metco pulley and belt.

However I believe you need an Oem crank for the metco to fasten to anyway.

I run a combination blower 10% overdrive and 15% under drive on my fox.

[Blackened300a]

If its an under drive crank and the blower has its own purely and belt. No! If its a single serpentine belt. Yes! If I remember correctly eaton swaps use a separate metco pulley and belt.

However I believe you need an Oem crank for the metco to fasten to anyway.

I run a combination blower 10% overdrive and 15% under drive on my fox.

I follow your logic. The accessories will turn slower because the crank pulley belt land is a different diameter. The center of the pulley is still spinning engine speed and since the eaton/trilogy uses its own belt and pulley that bolts to the center, the under drives shouldn't effect the boost. Just bolting the lower pulley to a underdrive pulley may not be possible.

[na svt]

The eaton pulley will not bolt to most aftermarket dampers.