Backfiring, dieseling and extended shackles

[ScoutIIMan@domain.elided]

Morning Digesters,

I get backfiring when there is an exhaust leak between the exhaust manifold 
and exhaust pipe. As soon as I tighten down the exhaust pipe, it's gone. I 
think what happens is that cold air is sucked in at the exhaust gasket 
ignites the fuel passing by.

A number of years ago I had a customer ask me to tune his car. He picked it 
up when I was done. He came back later that day, mad as heck, saying that his 
car still dieseled. I took it down the street and brought it back and it shut 
off just like it should. He took it down the street and when he got back, 
said it still dieseled. The long and short of it was that he'd pull in and 
just turn off the key, without letting it settle down. I told him to wait a 
couple of seconds, and then turn it off. Worked like a charm.

OK, now I've got a technical question for the suspension gurus out in IH 
land. I have some extended shackles that are for the front of my 74 Scout II. 
I haven't put them on before because, one, I like the nose down attitude, I 
didn't want to mess up my tracking. Well, I'd like to put the flat bar on 
(anti-sway bar) so I need these shackles. If I put them on, it shouldn't 
change the caster, but will increase the driveline angle a little bit, right? 
Will it do anything negative to my tracking/steering, etc?

STeve