to start with, I just drove my car home tonight, finished up all but exhaust.. Before i begin, my last engine was an over cammed closed chambered oval port 427 BBC, went 12.501 @ 117 with 3.73s.. sluggish off the line due to tight converter and to much cam.. well my 496 seen its first 25 miles tonight... and my ex-427" feels like it pulls harder.. I can be in drive, there is no kick down cable to tranny, and nail it from running 3500 rpm and with in ab 2 seconds it on limiter at 7k! but it feels like it lighting the tires up but there really not spinning.. new gear set is a 4.10 gears and 275-60-15, is it just the gear or am over turning the tranny which is a th350?? Or my next scenario: its now a stroker, Im running basically the same cam other than a few minor but important differences, the cam in the 427 was 660/666" solid roller 254/260 @ .050. on 110* LSA, installed on 106 ICL.. the 496 is 685/685 solid roller 253/266 @ .050 on 108 LSA I installed on a 102 ICL..cam card claims 3000-7500rpm, I never plan on turning past 7k... But through the grapevine I've heard Longer stroke will tame down a cams RPM capability so I got to thinking(it hurts to do so) this cam would be right in the ball park.. whether or not that statement is or application specific... The question I am asking is Maybe the tighter LSA and the early ICL peaking this engine to soon on the 4.10s? not sure if this is the right forum topic for this..

Maybe slipping trans but possibly driving out of the converter stall range or overpowering the efficiency of it.

Who's trans and converter are you running and what stall behind the old motor and where behind the new motor?

the old converter was a neil chance, supposed to went 3k, but it reality it went arround 2200 flash, i think the 427 having to much cam killed the torque which wouldnt allow it to stall enough, the new converter is the allstar performance converter, i bought down at steve kirks race shop, its was new and the converter stall, specs at 3500, doing a flash test being in first about 2 mph if i just stab it it jumps to 3400, the transmission is a sid neal trans, you may not be familiar with him but his link: http://www.nealtrans.com/racing-transmissions.html hes pretty reputable with his builds, but the tranny was built 3 years ago, still fresh only seen about 1000 miles with the 427. he only warrants his work for 90 days and is kind of out of the question to have him tear into it without spending money now.

Butt-dynos are highly inaccurate. Worry about what it's doing when you have some time slips to compare.

I kind of agree with the above statement but what your describing sounds like the converter is to loose. However, the converters you mentioned are inexpensive converters which appear to have low stall ranges as you stated. If you are correct with your stall ranges than it shouldn't be your issue.

I'm gonna say put the car on the track and diagnose a timeslip.