Need some ideas as to why a starter would clank.
Flywheel is new.
Starter is new.

The starter makes a terrible racket and clanks a lot when starting the car.

Background
I had this problem, but nat as bad when I had a neutral locked switch wired in. I took it out and the car started right up. No noise. Now the battery is in the rear of the car and then clanking is back and worse.
The starting circuit was not touched. Just the main power cable to the battery.

 

What size cable to the battery? Good size ground all the way to the front subframe? I run a #1 welding cable for both, with the neg. ending at the subframe, then a heavy ground cable from block to frame at engine. Some say a #2 is enough, but anything less than a #2 pos. and neg. cable will give starter issues.

 

really, ground to the front.
Ive never run a ground that far. I grounded to the rear frame rails. Figured the subframe connector would carry the ground.

I agree with welding wire. That is normally what I use but I had some left over old school phoenix gold 4 gauge cable that is better then welding wire. I have a new spool of 0 gauge just didn't want to cut that big of a hole.

Guess I will run a ground and use the 0 gauge. That sucks.
I hate working with 0 gauge.

 

Yes, really a ground to the front, unless you've got welded subframe connectors and solid alluminum body bushings. Then you might get away without the ground to the front subframe. I'm just grounding to the rear frame area on my Austin gasser, but it's got a full frame, so it works great.
If the connectors on your car are welded, then just be sure the ground is to the rear frame and not to the body at the trunk. Be sure to grind all the attachment points clean before bolting the straps down.

 

will add a ground today and see what happens.
Thanks

Every other car I have done this on had a full frame.

 

I have my battery in the trunk, with a ground cable to the rear frame rail. But my car has welded subframe connectors, so no ground issues. You could run a ground cable from the rear frame to the subframe if running a full length cable is too much of a pita. Just make sure you have good clean connections.

 

Also do you have the starter shimmed properly for your flywheel? They will make a ton of noise if not shimmed correctly. It does not matter if the starter you pulled had shims or not, the new one may need them. Also starters for a SBC are made more for the trans they are mounting with not the engine. If you had a SBC with a TH350 and changed to a TH400, since the 400 uses a different flywheel you need a different starter. Manual transmissions are the same way. The good 'ol 3510S starter will fit TH350, and TH700R4 (early) but not the TH400, TH200, or TH200R4. If you have a 3510MS it will fit TH700R4 (later), TH200, TH2004R but not the ones that the "S" starter would fit. This is due to the pitch of the gears being metric and not SAE, even tho the cone and housings of the starters are the same. If memory serves me right the TH400 uses a 3663S starter (dont quote me I am going off memory not my cataloges)

Massey

 

Starter did not clank when the battery was in the front and optima battery.
Starter is for the same tranny as the one in the car.

I cleaned the ground spot, it was a little rusty.
Also added a smaller (like 8 gauge) cable all the way to the block.
Also added a second 8 gauge power cable, so I have a 4 gauge
and an 8 gauge going to a distribution block. Then 4 gauge to
starter. Distribution block has been in there for a year, they work great and look clean.

Seems better, will test for a day or two. I should use a bigger
ground cable but I am broke till Friday. I had the 8 gauge.
It is high end monster cable.

Battery charger was saying battery at 100% at the battery and 80% at the ground.
Now, it is 100% at ground and 100% at engine block and starter.

Strange that low amps would cause a clank.

 

It does seem strange, as it will usually just crank slow, or click and not engage, but I guess it could be weak enough amps to just not let it engage and spin to mesh.
Had a friend just move his battery to the trunk on his Chevy and it clicked and chattered like crazy/ I looked underneath to check the ground and he had an "L" braket on the frame he had attached to, and although he cleaned his attachment, the other side of the L bracket was rusty and ugly. I took it off and ground around the hole, then eliminated the bracket and took the cable end direct to the hole. All worked fine after that.
It's amzing how much voltage drop you'll get with a little resistance, when you're only dealing with 12 volts to start! I always go overboard on all my cable sizes for remote batteries, and it's been trouble free.

 

So adding the small ground didnt help for long.
So yes I went overboard. I am tired or fing with it.

I ran 0 gauge from the battery to a distribution block on the firewall.
Then 4 gauge from the block to the starter.

for ground I ran the 4 gauge that I was using for power as
well as 2 more 8 gauge wires. Straight from battery to the head with the 4 gauge.
Then one 8 gauge to each side of the front sub-frame.
I got out a grinder and made damn sure there wasn't any rust.

Tried to start it and had the same issue? What the hell.
So I added a few bigger washers and started double checking everything.
The starter end wasn't really tight. It was snug but not overly tight.

So, I tightened the hell out of it and everything else.

Currently, the car starts right up.
So, I am not going to think about what would have happened
if I had tightened the heck out of the starter to begin with.

There was an issue with the ground because I tested the theory
by running a jumper cable from the battery to the block and
it started fine. I think I just loosened up the connection screwing
with everything.