Your not gonna get the answers you want.
Who knows the real condition of your A604.
Ryan has had issues at eleveated boost levels but others have been just fine.. There are lots of variables..
It might last just fine with 20+psi pulls or it might grenade with a 5psi pull.


Why not just keep a safe boost level (under 10psi) till you get the 5speed?
Do it right or expect problems...
Or just turn it up and blow the fuck out of the A604 for giggles and to force you to do the swap..
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1998 dodge avenger 4 cyl AT
Mods are:
Not enough