I found a kit that bolts into the offset starter holes and aligns the drill bit to drill a 400 for a regular type starter bolt pattern(not offset). Is this a good idea or am I going to run into problems doing this?

I already have a good mini starter but its not offset for my 400. Trying to save money here.

As long as the casting has enough material around the bolt hole area, I don't see why there should be a problem.

So somebody's making a template, huh? I just figured I'd use a tape measure and a carpenter's square. (But I'll do it with the block upside-down on the engine stand.)

You should be fine doing that any of the 400 blocks we have machined in our CNC machine we install that starter bolt hole with no problems. Just make sure that you counter bore the hole like the other bolt holes.

Anyone else had to do this.....I have recently acquired a second sbc 400 for my son and we need to use a mini starter to have header to starter clearance. Unfortunatley the block on ly has the angle holes for the starter mounting. I cant see a reason not to drill them and this is the only post I have seen on the subject. Anyone else had this problem or tried this before.

You should be fine doing that any of the 400 blocks we have machined in our CNC machine we install that starter bolt hole with no problems. Just make sure that you counter bore the hole like the other bolt holes.

The above advice is all you need. He works on these for a living.

Anyone else had to do this.....I have recently acquired a second sbc 400 for my son and we need to use a mini starter to have header to starter clearance. Unfortunatley the block on ly has the angle holes for the starter mounting. I cant see a reason not to drill them and this is the only post I have seen on the subject. Anyone else had this problem or tried this before.

Anyone else had to do this.....I have recently acquired a second sbc 400 for my son and we need to use a mini starter to have header to starter clearance. Unfortunatley the block on ly has the angle holes for the starter mounting. I cant see a reason not to drill them and this is the only post I have seen on the subject. Anyone else had this problem or tried this before.


As Carl stated it is not a problem at all
We do it to every 400 we machine that does not have the third hole with the only difference being we have a program to do it in the CNC which puts the hole exactly where it belongs.

As long as you can locate it accurately & counterbore it like the other holes you will be fine. :thumbsup:

OK I am confused why does a stagger hole head on starter
not work with 11 inch fly whl Or flex plate for that matter
why would a fat block heavy duty 4 field core starter not work
Blocks dont have three holes?? Or is this a 400 thing?

OK I am confused why does a stagger hole head on starter
not work with 11 inch fly whl Or flex plate for that matter
why would a fat block heavy duty 4 field core starter not work
Blocks dont have three holes?? Or is this a 400 thing?

Most aftermarket "mini starters" need the straight bolt pattern & many 400 blocks do not have the outboard hole from the factory

Mini starter that much better? Or is it a room thing?
If not a big block starter would work ?

I have also done it; as described above, making sure that the proper counterbore was included, so that "real" starter bolts could be used.

The usual reasons are either the "mini-starter" thing; or, the need to use a 12.8" flywheel. The deal with the smaller flywheel makes perfect sense, as to why there's no "special" starter somewhere that you can buy that will bolt to the 14" bolt pattern but work on the 12.8" wheel, if you just think about what that means for a minute. Since the wheel is smaller, that means that the starter shaft and drive must be located closer to the crank CL by half the difference between those diameters, which is close to 5/8". If you look at where the inboard bolt for the 14" pattern is, you'll see that if the whole starter innards are moved that far over nearer to the crank, the inboard bolt of the 14" pattern would have to go RIGHT DIRECTLY THROUGH THE MIDDLE of the starter drive in its new home. Unless of course you know where to get bolts that have an "offset"... I used to, in fact they were on the shelf right next to the drill bits for square holes, but that store closed, and nobody else carries either of those things any more. ;) So the only possible choice for putting the starter for the smaller flywheel on a block that was made before that pattern was introduced in about 1978 (unfortunately, there's no such things as "features from the future" that magically appear on blocks, either) is to add the inboard hole.

SB and BB starters are the same, just like distributors are. 3510 is the aluminum one, 3560 is the cast-iron one, 4347 is the one that fixes The Starter Bolt Pattern Problem, where the whole 14" pattern is drilled too far from the crank. Of course, if you're careless about drilling the extra hole, you can create that Problem yourself, which would be a bummer.

Yes reduction-gear "mini-starters" DEFINITELY are "that much better". In fact, they're even better than "that much better". I will NEVER AGAIN bother with one of the old Delco direct-drive POSs from the Stone Age; I enjoy being able to start my car whenever I want to too much.