83 C20 Crew torque converter replacement

[Strick]

Hello folks. I am working on a C20 Crew for a customer that had his engine built elsewhere. I have it running and it sounds great. I've pulled the distributor a couple times now and have it timed so that it no longer pops through the carb and through the exhaust as well. I don't know the specs on the camshaft and am suspect that the timing chain has had 4 degrees advanced seeing as how I've had to move the distributor twice from what would normally be TDC on a stock engine.
Adjusting the valves and timing has it running and it takes the accelerator well in park. Even with it idled at 1500 rpm, it shuts off immediately when pulled into reverse or drive. I can retard the timing and it will stay running a quarter of the time but it has absolutely no power and then pops through the exhaust and carb when trying to drive. This has led me to believe that it needs more stall speed from the converter.
The customer is Hispanic and my Spanish is almost as good as his English. I've had a difficult time getting him to understand that the engine part of the the tune is good but unfortunately the tranny has to be pulled in order to replace the converter. Without any specs on the engine itself I am guessing as to what converter to use.
I just built an SBC last year with a .460 lift cam and had no issues when using on my K5 with TH350. I'm going to suppose that this monster has .480 lift or better because it does not like to idle below 1500 rpm.
Thanks for the advice guys and let me know what you think.

Strickland

 

[bucket]

I'm going to assume something is wrong. I've got a few engines with 480-500 lift and a little bit of duration, they will idle and go into gear just fine with a stock or super mild converter. And they are just 350's.

 

[GTX63]

I'd spend a little time tonight on Babel and write up a list of questions that he can read tomorrow morning. Then put them into Babel so you know what he is talking about.
Diagnosing what you have described could go in 36 different directions, and I would not put a torque converter at the top. If you are finding issues with timing that lead back to the engine builder, then it likely points to something fairly common, and due to builder error.

 

[Strick]

This is a 350 also. I can pat the accelerator & get it to go but it is brutal on the mounts & tranny. I've unplugged the booster & capped the line with same result. Even at 1500 rpm the engine kills when pulled into gear.

HS