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Discussion Starter · #1 ·
Hey yall, im posting because recently i was asked to help complete an already mostly built project car. The car is an 1987 Mazda Rx7, with a SBC 350 and 4 speed auto. When they first bought the car, im pretty sure it had a 305, because when i ran the numbers for the trans, it comes back as a 200-4r from 84 based on the date code. There's a few other signs that point to the original engine having been a 305, im guessing whoever built this car first, probably pulled the engine/trans combo from a G-body monte carlo or something alike.

The engine the car came with blew up, so they sourced out a 350 from a 1996 Chevy Tahoe ( Casting No. 10243880) and installed it. This is where they asked me to come help finish the project. The flexplate is new, not sure of the brand but it's from a local parts store, for the 96 Tahoe. The starter is a summit racing brand high torque mini starter, i can't get the exact part number right now because somethings up with summits site.

The first issue, is that the starter bendix is constantly engaged against the flexplate and by a good amount.

Second, the bolts for the 200-4r torque converter are a fair amount smaller than the diameter of the reliefs in the flexplate, after some quick research the 4l60/700-4r the tahoe would have came with, would have had larger diameter bolts for it's torque converter.

Lastly, the gap between TC and flexplate is almost at what i would call the limit. The TC cannot seat all the way against the flexplate because it hits the crankshaft hub/ bolts. There's slightly less than the thickness of a box wrench, with even what i would say is the standard spacer, it would be as thick as said wrench. That seems excessive to me.

I would really appreciate some input on this, not sure what direction i should go from here with this huge mix-match of components.
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Discussion Starter · #3 ·
20b or 26b will give you better power.

But dealing with what ya have the torque converter can use a spacer but sounds more like a mismatch of parts? Too bad as that is a fantastic handling car with outstanding brakes. Take out the starter as a bendix is easy to replace. Take it with you to the parts store.
I should have mentioned i tested the starter bendix and it appears to be working fine, i don't think its partially engaged or sticking at all. Also the starters a summit brand mini starter, local parts stores can barley help with basic stuff anymore, this would be beyond them lol.
 

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Discussion Starter · #9 ·
Eric thank you, i'm remembering now i had to setup the starter on my olds 403 the same way.

49' Coupe, i checked and they do have the flexplate installed correctly, counterweight towards engine, raised reliefs towards TC. Flex plate is right for this engine, but not exactly right for the TC. This Flexplate does have a dual pattern, 3 holes spaced farther out, and 3 more to accommodate a smaller TC like the one that's currently in the car or so it seems.

BogiesAnnex, i actually pulled and bench tested the starter, it's working correctly. This particular one uses an external solenoid btw, it's mounted on the firewall like an old ford haha. Electrically everythings working in the car. I think the issue comes down to this starter not being shimmed correctly for this setup. This flexplate may also be somewhat of a mismatch for this TC as well i believe.
 
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