Installing 455 to a th350bop What fly wheel do I need 455 or 350? There seems to be a gap between the converter and flywheel?
You need a 455 flex plate of course. There should be a gap between the flex plate and converter pads. It should be more than 1/16". Make absolutely sure that your converter is fully installed onto the input shaft. It MAY not be.
That's exactly what I am talking about. The converter is not properly seated in the transmission. There are 2 sets of splines that the converter engages along with the 2 notches in the converter snout that drives the transmission oil pump.
When you install a converter, you should first line up the 2 notches in the snout with the drive tangs of the pump. Then you need to spin and push on the converter until it drops down 2 more times. When the converter is fully seated, the measurement from the bell housing flange to the converter should be 1 1/8" (THM350) according to the chart I posted in my previous response
Possibly, OR, one of the 2 sets of splines haven't engaged. There are the input splines and stator splines and the 2 notches in the converter snout.
Live and learn. Next time, make sure you seat the converter properly. Then use tape or fashion something to keep it fully engaged. It can come out as you are trying to mate the transmission with the engine. If you look in the Chassis Manual, they even have a tool for that. They call it a Converter Holding Strap Tool J-21366.
Lot's of folks have done exactly the same thing. When I first started with serious work on cars, I was fortunate enough to watch a guy in a transmission repair shop break those off and then, after the air cleared, he replaced that inner gear. I paid really close attention to his next attempt to put the converter in properly. Learned a whole lot that day.
