LM7 383 Build Up

[blackout]

Well I have an update after putting 1500 miles on it.

The new engine runs good. But it seems to lack some of the low end grunt that I want. It takes a bit of RPM and throttle to get it moving. And seems to always need a lot of throttle to keep it moving up hills. It seems that it sometimes has trouble getting into OD while cruising. Is this a product of my cam, torque converter, gears, maybe all three? It is fast from 3k RPM and up.

5500 lb ECSB truck
4wd
32 or 33in tall tires on 18 wheels
383 cubic inch
3.73 gears
220/220 .556/.556 114lsa
4L60E running a shift kit & Trailblazer I-6 Torque Converter
3.73 gears


what do you guys think?

[PitchBlackC3]

Well I have an update after putting 1500 miles on it.

The new engine runs good. But it seems to lack some of the low end grunt that I want. It takes a bit of RPM and throttle to get it moving. And seems to always need a lot of throttle to keep it moving up hills. It seems that it sometimes has trouble getting into OD while cruising. Is this a product of my cam, torque converter, gears, maybe all three? It is fast from 3k RPM and up.

5500 lb ECSB truck
4wd
32 or 33in tall tires on 18 wheels
383 cubic inch
3.73 gears
220/220 .556/.556 114lsa
4L60E running a shift kit & Trailblazer I-6 Torque Converter
3.73 gears


what do you guys think?

The RPM and throttle to get it moving are because of the stall.

Are you sure your converter is locking at cruise?
Do some logging. A significant enough misfire count can keep the PCM from commanding TCC lock up.
If your RPMs surge with every hill to maintain the same speed, your converter isn't locked.

[blackout]

The RPM and throttle to get it moving are because of the stall.

Are you sure your converter is locking at cruise?
Do some logging. A significant enough misfire count can keep the PCM from commanding TCC lock up.
If your RPMs surge with every hill to maintain the same speed, your converter isn't locked.

hmmm interesting. what would cause this misfire count?