Re: 305 vs. 350 TPI 730 EPROMs

["Bruce Plecan" <nacelp@bright.net>]

> Why is it that the 305 has significantly more advance in the spark tables
> compared to the 350 (1991 F-Body 730 ECM)?

Poorer combustion chamber (or in general poorer flame progression)...

  Could the use of the 305 spark
> tables in a PROM for a 350 produce excessive knock retard?

Depends on the new engine.

> I am asking because I have a friend who is experiencing significant knock
> retard in his 1991 Z-28 305TPI automatic.  This car has a transplanted 350
> (w/ 350 knock sensor).  Although the car has a custom PROM in order to
work

custom usually means trust us it's right, yet they haven't looked at your
car.  Hahaha.

> with his 19lb injectors, I have noted that the spark tables are basically
> the 305 tables.

Probably are.

 Furthermore, he is still running the ESC filter that is
> attached to the 305 MemCal.  Is the ESC filter on the 305 MemCal tuned for
> the 305 engine?

Yes.

  Would he need to be running an ESC filter that was designed
> for a 350?

Need to check with the plugs on that, no tuning ability use the oem set up.

  As a side note ... this car is not in need of fuel.  The O2
> values at WOT show > 920 mV across the board.  In fact - the car is
actually
> running rich right now.

Reading an O2 (gm oem one) for mixture is just as accurate as reading tea
leafs.
Grumpy
>
> Tim
>

>