I am installing the 340 HP exhaust manifolds on my 1970 Challenger. The factory service manual says not to install the conical washers on the center ports for each side. If I put a washer on the center port bolts there is only about 3/8 of threads to engage the head. I purchased a reproduction bolt set so this leaves me with four extra conical washers. Is this correct?

i used the washers on the end studs only

They only go on the ends, where the studs are. I even use them back on headers!

Yes, ends only. Keep the extras as spares.

OK, thanks for the info.

Just did a 71 340 Duster and used the washers on all the bolts and studs. The reproduction bolts are 1/2" shorter than the factory bolts! I used the originals because they were in good shape and everything worked out well.