Bog and knock 1800-2400RPM, 60 - 95 Kpi MAP

[ezusmanis]

I recently made changes to my 95 GMC Yukon (170K miles) with 5.7TBI which required some retuning.

I adjusted the timing tables by raising cell timing by 1 degree until knock is detected and then backing down 2 degrees.

I adjusted the VE tables using the BLM values acquired during quite a few data scan runs.

The problem I have is that the engine bogs between 1800 and 2400 RPM and a data scan indicates .5 - 2.9 degrees of knock retard during some of those times. The BLMs in that range looked good (128 - 130) so I tried backing off timing in that range but it didn't help. It kind of feels like it's going lean in that range.

I thought about adjusting the 'proportional flow gain factor vs. MAP vs. RPM' to increase flow in the problem range but I was wondering if someone had any better suggestions!

Changes:

Edelbrock 60859 heads (got great deal on mildly used heads)
Edelbrock 37004 intake manifold
Comp 1416 Roller tip rockers
New lifters
+.1 pushrods (recommended by Edelbrock)
TBI spacer
New thermostat, wires, distributor, cap, rotor, water pump
Switched to Champion RC12YC plugs per Edelbrock recommendation
40kV ignition coil
Shorty headers
New O2 sensor, knock sensor, oil pressure sender and both temp senders
Cold air intake
Gibson exhaust