Does anyone know what size bolts I need for connecting manifold to flange on a 99 3.9L v6?
and how much trouble is it? Tnx!

 

When i did mine i used 3/8". The hard part is geting the old ones out.

 

be sure and use anti-seize compound on ALL bolts on the bottom of your truck. dont forget brake tubing nuts

 

tnx guys! I'll try to get them out this next wkend...

How LONG are bolts do I need? I'm guessing about 2.0 in to 2.5 in??? and do they have special head???

 

I just did mine on my truck and it was a pain in the *** untill I took off my tire and my plastic inner fender well then it became so much easier where I used my grinder to cut the bolts.

 

long time ago i had a slant six. i used 3/8 bolt on the flange, but they kept coming lose. i figured out the bolt should have been 7/16 dia. so if it comes lose check a truck that is stock.

 

Is it the stock manifolds that are rusting,or do you have headers on there now?
If the pipe rusted to that piont,it is only a matter of time till it all goes.
Plus you do not know how far up the pipe you will have to go to get to good metal.
I would just replace them.