Adaptor plate for ecotec to 6L50 What material to use?

[Lex]

As heading states, anybody know what to make an adaptor plate out of?
Friends have said t6 18 mm aluminium plate.
I'm having a hard time sourcing this material.
What about t6 18mm x 100mm wide lengths? Less waste.
Does it need to be surfaced, machined flat?
Better still, anybody know who makes adaptor plates?
Appreciate any help, thanks.
Lex

 

[EYY]

What for? Adaptor plates are generally bad news. Converter is moved away from the flexplate - so it won't locate properly unless you have a spigot made up but still not the best case scenario. Also need to add spacers between flexplate and torque converter. Transmission will be moved back so need to make sure tailshaft will work (depends on what box you're going, do you mean 5l40e?) and the holes for transmission mounts may need to be altered.

They're generally not that great for alignment even if you do get everything right. With the old 304's and 308's the best way is to have the block redrilled to the desired pattern, but it costs $300 to $400 usually. I'm not sure if that's possible on the ecotec though. It'd rely on the pattern being very similar to the factory auto.

Any reason for the change? The 4L60e's are a very capable box and arent all that fragile.

 

[Lex]

Thanks for the reply.
Transmission is as stated 6L50.
Have an old ecotec motor & the 6L50 sitting on the work bench.
Torque converter centre fits on the crank bevelled face. Three bolts line up & fit t/c to flex plate (other 3 have to be drilled). There is 6 bolts on 6L50 t/c, which is why ecotec flex plate has to be drilled.
When tranny with t/c is bolted to motor (only at the t/c to flex plate) there is about 10 mm from flex plate to engine.
Reason for fitting, more fuel efficient & something to do. Modernising an old car.
Hope this is understandable.
Thanks Lex

 

[Lex]

Hi
I rang Castlemaine rod shop, said to use, for example, if l have 10mm between engine & bellhousing, use 12mm plate steel, then mill it each side, to bring it back to 10mm. It has to be perfectly flat.
I think that will bring the cost down.