I was replacing the entire fuel system on 68 c10 and when I pulled the fuel pump off I noticed the oil was milky, I'm assuming a head gasket is bad but I'll check compression today. My question is should I go with the original 327 or rebuild this 350 that somebody put in it. The intake # says it's 72-77 year.
Engine Time Pull the heads off both engines and figure out which one has the better bore then decide . The compression should be above 125 # to run well , over 135 # and it'll need premium fuel and careful attention to ig notion timing . Both are dead easy to overhaul , often you needn't rebuild them atall , just carefully take apart and replace what's used up or worn out . If you want it to drive nicely and still have gobs of power , use a 3/4 or 1 ton stock camshaft from a 1967 with automatic tranny . " racing " cams always (no exceptions) make it no fun to drive and you'll wind up selling it soon . Choose carefully and enjoy the next 40 years of pleasurable and economical Motoring . As long as the bore isn't tapered more than .008" you shouldn't need to bore it . I always replace the pistons , cam shaft and lifters . Who does and how much you spend on the cylinder head re work , will give you the very most bang for your buck .
The compression is 110 across the board, I was checking the timing and took the distributor cap off to see where the rotor was pointing and the rotor and dist. shaft have quite a bit play in it, I was told it advances 10? when opening throttle but there's way more than 10? of play in the rotor. My original problem with my truck is that it will start and run but will die when giving it throttle.
I have the exact same problem with my 72 c20. I thought it may be a vacuum timing advance issue, when i opened the distributor to check it everything was rusty so i just replaced the whole distributor. Still have the same issue with the truck shutting off when i apply throttle. Im going to clean and rebuild the carb next. Hopefully that helps. Keep me posted if you solve your issue.
Flat Spots Kim ; The vacuum advance only gives you 10? advance , the mechanical flyweights under neath give you the rest ~ This is why it's important to have _NO_ vacuum signal to the Dizzy @ idle but as soon as you touch the throttle , it gives you vacuum ~ most folks don't get this and so mis connect the vacuum hose to the wrong carby port . Also , it is important that the *instant* you begin to open the throttle , the accelerator pump squirts out a GUSH of fuel , not a dribble nor a mist ~ you should get this when you open the throttle ~ no need to yank it as fast as you can...
What carb port does it connect too? Mines connected to a double port on the lower left hand side in the back of the carb.
Vacuum Advance Port The only one that has vacuum as soon as you open the throttle..... It moves around depending on the specific model of carby fitted to your engine but here's a way to see if it's dead wrong now : Disconnect the dizzy's hose with the engine at hot idle , if there's any change in how it runs no matter how slight , it's mis connected . If you hear the vacuum hissing when you disconnect the carby's hose or rubber cap , that's not the right one , keep looking , often it's on the back side of the carby where you'll burn your fingers ....
The brand new carb was flooding it, put on another carb on and it started right up, retimed it cause it was way out of time. Runs great now. Thanks for the advise everybody.
Flooding Prolly just a tiny bit of crud in the float valve , easy to remedy , this is why a filter just before the carby is so important ~ America always has low quality , filthy fuels .
