question about converters

{You guys came up with some good stuff..few answers in no particular order. GEARS: 3.55:1. Timing: the engine builder was over Monday and did a THOROUGH check of what he could. Total advance and idle timing are just fine. Compression check shows we are perfect on all 8 cyl. SECONDARIES: adjusted and working Ok. Primary metering rods changed to richer and lighter springs. Also tried 3 carbs, mine works best.} Some research from today: Again talked to them at Dynamic. (Im learning much about converters) They take the information provided-and you needs to be accurate-and they do the figuring. being this is a high torque stroker application and not a stock or "bolt-on" mod 340 the correct converter will ask to stall at a very very high rpm. By nature of their design-the 11" street converter (live and learn) is pushing the advertised 2600 rpm stall speed to its lowest extreme, if not lower . My motor, as built, is asking for 3800-4000 rpm stall. He says it will seem like Im losing 75-100 Hp. with the 11" street converter. My friend Greg's R/T Chally 383 (engine built by same guy, he uses the 9 1/2" Dynamic) can smoke them off idle. We virtually have similar HP/Tq figures and just 10 C.I. difference. Also: had 1/2 hr chat with a chassis dyno tuner/experience musclecar and drag racer today prior to scheduling an appointment. To summarize: after a give and take of detailed information like cam specs,compression, cubic inches, exhaust, weight, tranny, gear ratio, ignition etc.......he didnt even pause for a second and said I needed the 9 1/2" converter. He said with the 11" it "must feel like your towing a car on a trailer behind you". He uses the Dynamic converters exclusively for street/strip or strip only. He says mine is a worst case scenario for chosing an incorrect component. (Adam is right about the stock converter stall speed, 1800 RPM) However the construction is way different than a Dynamic due to the pitch angle of the fins internally. Thus the ability to spin wheels off idle and create at least a minimum stall. . However you suffer with slippage at cruising RPM, poor economy, heat buildup. My last potential issue could be chosing to use factory manifolds for a stock look. We couldnt test with them on the dyno due to fitment issue. I was figuring it would kill me by at least 20 hp & tq. (from what I have read from prvious test) and can live with 410 HP if thats the case. Chassis dyno tuner says at this level with some headwork and my cam specs like I have he has seen it hurt performance 25-50 hp from idle to peak rpm . He told me before I do this (chassis dyno) to swap converters at least because the chassis dyno results "will make me sick" . I should expect a 22% loss with auto trans and should be @ 345 RWHP if I used the way too small 1- 5/8" cheapo headers like on the dyno run. My current 11" converter and manifolds may limit it to 250-260 RWHP. :( Not good. So it looks like Im about to find out how important the correct converter is. $$$$$$ I may need to steal from the basket at a local church Sunday-keep an eye for my name in the police blotters!