I recently purchased and attempted to install the above headers. I say attempted because while the drivers side bolts up no problem, the last bolt on the passenger side does not line up with the hole in the block (the one closest to the firewall). It is off by about 1/2 an inch, while all the others line up fine.

I have a remanufactured 305 in the car, but the old manifolds were put on when the block was dropped into the car. Does anyone have advice as to what I can do? I only have regular access to hand tools, but if need be I can nurse the car to a garage where i can get more tools.

 

You need heads that have the original SBC exhaust bolt pattern. You could drill and tap the missing hole in the head and plug the extra one. I'm surprised that you're only having this problem on one side, have you got two of the same heads, or are they different?

 

I had this problem with my 400 when I dropped it in I needed to use the stock manifolds for a bit, but the last bolt on the pass side didnt line up just like yours I ended up ordering a set of headman headers and the bolt pattern was good for me, You might want to check the casting on the manifolds and see if you can figgure out if you ordered the wrong headers for the car. But besides the drilling and tapping idea I cant think of anything else though sorry.

 

now, I ordered directly from summits website, and I had used my exact car specs for the actual search (i.e. pontiac, firebird, 1989, 305) and they were the only summit branded headers to come up. Has anyone else had this problem with summits headers, or what is a decent pair of shorty headers and matching y pipe I can get relatively cheap. (Unfortunately I do not have the money to get a pair of jet hot headers yet).

 

Is the hole in the head too far forward, or too far back?

 

sorry, i thought i had mentioned that part. The hole in the head is too far back
----------
I actually did check prior to installation, the headers match each other. Also, if the original manifold was put back on, wouldn't that automatically make it an original sbc bolt pattern? I assumed so, but if I knew it all i wouldn't be asking

 

double post sorry

 

At some point, GM decided to move that bolt back. I'd thought that the newer heads all had both holes drilled and tapped to mount either style of exhaust, but I guess not.

 

I believe you're right. Both my 88 and 92 heads had both holes drilled and tapped. Maybe his heads were changed.