I have the 68310's on my car. I found installing them from the bottom was the way to go. I removed the z bar and oil filter and the spark plugs and it slipped right in on the driver side. No modifications needed.
The right side required removal of the spark plugs and starter. I ended up using a mini starter from a 96-97 LT1 F body. I found that you fish the header in and leave it loose. Then install the starter AND then install the header. I did not like the prospect of running the positive battery cable through the header tubes (which is where the stock cable would go). I used a longer positive cable off of a late 80's B body. I ran it around the mechanical fuel pump and along the right side oil pan rail.
The other thing I did was I had to use a different oil dipstick tube (my 78 had a pan mounted dipstick on the left side). I used a dipstick from an 80 with the tab relocated.
The right side required removal of the spark plugs and starter. I ended up using a mini starter from a 96-97 LT1 F body. I found that you fish the header in and leave it loose. Then install the starter AND then install the header. I did not like the prospect of running the positive battery cable through the header tubes (which is where the stock cable would go). I used a longer positive cable off of a late 80's B body. I ran it around the mechanical fuel pump and along the right side oil pan rail.
The other thing I did was I had to use a different oil dipstick tube (my 78 had a pan mounted dipstick on the left side). I used a dipstick from an 80 with the tab relocated.
