Hey I'm new to this so plz bare with me I just had a mechanic swap 305 to 350 didn't change any of those parts as described in the other post so my question is with chip or witch ecm should I switch to .....and another problem I am having is on take off around 20 to 30 Mph when I floor it it revs real high so I have to let off the gas or I feel like motor is gonna blow lol...any ideas on this any help will be appreciated

 

What car did you have, TBI, TPI?, carb?

What is on the new motor for induction?

 

Mo info needed.

 

It was the 305 Tbi to the 350 tbi

 

305 Tbi to 350 tbi

 

1991 chevy silverado

 

So you have the stock Chevy silverado induction system on the engine now?, Are you using the computer as well

 

WHICH other post? There's thousands on this web site.

You're saying your "mechanic" put in a 350 but didn't change any of the calibration items like injector sizing or ECM/prom? Your "mechanic" is an idiot. You're going to need the injectors and ECM/prom for a 350 in your vehicle at minimum. Be sure the calibration includes the transmission type you have and the appropriate gear ratio--an ECM/prom for 4.11 gears won't play well if you have 3.42s.


Trans slipping?
Trans not upshifting properly?
Trans works fine, you're not used to how it is supposed to sound?

No way to tell from here.