Hello everyone,
My name's Grant and I've been lurking on this board for awhile, but never had a real need to post. I've searched on many different topics and answered many of my questions, but now that the time has come for me to actually build a decent engine, I really need help sorting it out!
I inherited an '82 D150 with a 727 from my grandpa a few years back, and have been slowly returning it to actual daily-driver status. In the last few months I've done an HEI conversion (NOS distributor), stripped all lean-burn from the system, replaced the computer carb with a Holley factory rebuilt 1945, ditched the air pump and modfied the cat. It runs beautifully, except for the horrendous smoke that has started spewing after it warms up and the deadly sound of a knocking main bearing.
The engine is original and has 152k on it, but it has sat for years, so there is no telling what level of crud is in the bottom of it. Even though I changed the oil a few times I think I just managed to loosen up some gunk that is now blocking a passage somewhere. So, it needs a rebuild.
I bought a second engine, supposedly from an '84 truck, but upon disassembly I found a cast crank and solid lifters, so I'm assuming late 70s engine. I would like to rebuild this one if I can. Under the gunk it was also sporting factory blue engine paint, which I know my '82 doesn't have (black).
The engine is completely torn down, and filthy. I plan to drop it off at the machine shop later this week to have it cleaned and boiled, and then check where I'm at with the bore. It has a healthy ridge in the top of the cylinders, but I've read these things can take a serious overbore before issues, so I'm thinking I'm OK yet.
Here are my questions:
1) The exhaust manifolds on both engines are cracked. I need something new, so what would be the best bang for the buck? Just another stocker?
2) The stock intake manifold was a 1bbl aluminum piece, and the second engine has a 1bbl cast iron one. Should I use either? Should I modify one for use with a 2bbl? Or ?????
3) Headwork: I've read about oversize valves and cutting the head for compression. I'm planning on flat-top pistons, and I can CC the heads and check deck height (not my first engine build, but definitely my first slant). What do I want for a truck? I'd like to run regular gas in it, but if the HP gains are worth it, premium is acceptable. I plan to port the head on my own.
4) Cam/lifters: this seems to be a topic with a lot of debate. I've read a lot of the threads, and I'm still not really sure which direction I should go. Should I go new? Should I go with a regrind on my stock cam/lifters? They don't look bad, but I don't know how much this limits me on cam specs if I use a stock core.
5) I have access to a lot of fabrication tools/machines so making/modifying things aren't really an issue. All I want is a good, reliable truck engine, and if I can pick up an extra 60-80hp that'd be great too.
I will upgrade the exhaust after the build as well, so that's not an issue.
Thanks for your help,
Grant