318 power?

I was going to build a 377 of a 340 block I have, but couldn't find any this spring so I took what I have to get the car running so I can sort details out for next season. Plan is to build a mild and reliable mid to high 6's car for Swedish Street Week. The 377 will have a mech cam and tunnel ram on top and a 46RH tranny. And perhaps Trick Flow heads.
I have everything except pistons for the 3.58 crank into a 340. I’d love to get started on mine now, but, there’s always something in the way. (LOL - groooooan)
I do like that combination of the increased stroke and big bore.
I have two converters:
1. Hughes #24-35
2. The one in pictures. Does anyone know what it is?

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Darn tiny!