At W.O.T. right before the engine shifts at 5300-5600rpms it bogs down/stumbles into the next gear then it picks right up til right before the next shift and does it again.

My trans is a rebuilt700r4.

ENGINE STATS AS FOLLOWS:

383 L98 TPI

Engine:

350 bored .030 over truck block 4 bolt main, line bored, magnafluxed, cylinders honed

engine internals balanced

Engine Modifications:

Stock plenum ported/simeased for the runners and throttle body

Edelbrock intake manifold and runners ported and simesed

Edelbrock Performer heads ported 64cc & 160/202 intake/exhaust

Edelbrock Valve Covers

Moroso valve cover breathers

Edelbrock BBK 58mm Throttle Body

Racetronix 37lb. Injectors

Walbro high performance fuel pump

Holley adj. fuel pressure regulator

Manly Pushrods

Crane 1.6 Roller Rockers

Comp cam Hydraulic roller:
510/540 gross lift 1.6 rockers bump up lift to 576
Duration at .050 intake:230/exhaust244
Lobe separation:112

Federal Mogol Sealed Power Speed Pro 10:5:1 forged pistons

Sealed Power Chrome Molly rings

Eagle forged piston rods

refurbished truck 400 crank turned down polished and balanced

Power Force harmonic balancer

Moroso 6qt. Pan

Edelbrock water pump

MSD HEI distributor with cap & rotor

MSD Blaster coil

MSD box 6AL with rev. limiter

Accel 8.8 wires with heat retarded sleeves

Autolite short plugs for header clearence and cooler heat range

Hooker 2210 long tube coated headers 1 3/4

Mufflex 3.0" Exhaust System

3” Flowmaster Race Series muffler

SLP cold air induction

K/N air filter

Grantanelli adj. Mas air flow sensor

 

Also I did reset the IAC, and set the TPS at .054. I have rasied the idle to 8-900rpm in park, and in drive its about 750rpm.

 

Well I e-mailed Racetronix where I got my injectors from asking them about fuel pressure. They said I should be good at 43.5PSI, I have mine set at 45-46PSI. So I'm going to lower down to 43PSI and see if that fixes the problem.