Originally Posted by
Gary Lewis
I've not been talking about the "bottom end", which usually means the crank and bearings, but the pistons. If the engine has stock or stock-style replacement pistons then you may not have more than stock compression. And if a high-lift/long-duration cam was installed with stock compression you won't have much power.
But finding out what you have may not be easy. The first step would be to ask the previous owner what the pistons are and what cam is in it. But if that doesn't work look at Edelbrock's website and see what the chamber size is on their heads. Then find out what it is for stock heads and what the stock compression ratio is. That'll give you enough info to back into the stock piston dome and in-the-hole volumes and then you can figure the CR with the Eddy heads.
Understood about which "bottom end" we were discussing. I texted the previous owner and asked him if the pistons were ever replaced or I'd the block was bored out.
In the mean time, I got the truck hot and adjusted the idle air screws a little closer "to the book" which was about 1 1/2 turns out from bottomed out. Also adjusted the idle and moved the linkage from the top hole to the bottom hole on the plunger. Seems to feel a little more powerful in the lower rpm range.
I've decided to still do the cheap stuff while I can. Plugs, wires and a fuel filter. The previous owner is using a GM style distributor on the motor, which I know nothing about. Come to think of it, just add that to the list of things I know nothing about lol