Brad96

iTrader: (1)

I'm trying to replace the big, heavy direct-drive starter in my '91 Trans Am with the lighter LT1 Corvette starter, part# 10455709. But, this gear-driven starter doesn't fit my engine block. The bolt holes line up fine, but the starter casting runs into the block before the starter pulls up flush to the block surface. See the attached pictures.

I made a crayon rubbing of the block surface, then cut it out and transferred it to the starter, to show where it interferes. It looks like I would have to remove quite a bit of metal from the starter housing to make it fit, which is a little scary.

Has anyone else run into this problem? I have a non-stock Gen1 SBC 350 of unknown year. Maybe I have an unusual engine block?

Lurbie

iTrader: (3)

I've not had that problem, but I used a starter for the 96 Camaro LT1, it fit fine. Keep in mind the blocks are sand cast and the outside of the block is unmachined, as-cast, product. Maybe the casting was lacking a little in that area, allowing more metal than needed. I'd say you've got 3 alternatives, get a different starter, remove metal from the starter, or remove metal from the block. If it were mine, I'd probably remove some from the block first, if you're not able to take the starter back and exchange it for something else. On a side note, I'd guess you've got an intermittent misfire by the looks of that burnt up spark plug wire.

DynoDave43

iTrader: (11)

I seem to recall a thread on here where someone with a Summit mini starter ran into a similar problem. They shaved the needed amount off the starter and it worked fine, but were disappointed in having to do it.

sofakingdom

iTrader: (1)

That block looks like it has a bulge in a most unfortunate place.

Years ago, that particular quality control deviation didn't matter, so nobody really paid attention to it.

I'd recommend trimming the block rather than the starter.

Brad96

iTrader: (1)

Thanks for the replies. I was thinking it would be a lot easier to trim the aluminum starter housing, which I could do on the bench, rather than grinding the iron engine block, from underneath the car. But, I suppose that removing metal from the block in that location is less likely to cause any functional problems, allows me to return the starter if it doesn't work, and allows the next starter to fit without modification when this one eventually needs to be replaced. I'll see what I can do with a die grinder.

I ran a search, but couldn't find the thread where another member had the same problem with a Summit mini starter.

Lurbie, you're right. When I pulled the old starter, I noticed that several wires were too close to the headers. That one plug wire has a nasty burn through the insulation. There used to be a plastic wire separator in there, which has melted into a little glob. Surprisingly, I haven't noticed a missfire, but I need to replace some wires, and tie them out of the way.

sofakingdom

iTrader: (1)

Yup; always hack on the thing that's messed up, NOT on good things that won't fit because the other is messed up. Kind of, a good rule to live by; not just for car parts, but life in general. Car parts are just a commonly occurring instance of the universal principle.