73 345 V8 information
- Thread starter 73Beast
- Start date
FDChappie
Well-known member
Just did my engine last spring. I went to 4 bbl Holley 390cfm carb, comp 252 cam, .020" bigger pistons, bumped the compression to 9:1 and used a set of non smog heads. I'm real happy with the power.
This is a truck engine designed for torque and the pistons it's equipped with have steel inserts on the first ring land for strength under load. That limits rpm's to around 4.5k. Light weight pistons, stronger valve springs and a balance job will get you to around 6k max. Basically there is a lot of iron spinning in this engine and it can only safely spin so fast. What are you hoping to accomplish?
This is a truck engine designed for torque and the pistons it's equipped with have steel inserts on the first ring land for strength under load. That limits rpm's to around 4.5k. Light weight pistons, stronger valve springs and a balance job will get you to around 6k max. Basically there is a lot of iron spinning in this engine and it can only safely spin so fast. What are you hoping to accomplish?
Scoutboy74
Moderator
Welcome to the forum. 78k is nothing for one of these engines if its been well maintained. Even poorly maintained ones will routinely log twice that many in their sleep. If the engine is healthy, a rebuild would likely be a waste of time and dime.
There are rebuild kits available. Performance? Out of an IH engine? You haven't spent much time reading on these forums. IH engines are great when used as originally intended. They were built with longevity and durability in mind. They aren't performance mills. They move heavy loads slowly, all day long, every day of the week, and twice on Sunday. Yes, gains can be made, but they are meager and come with an enormous price tag. A lot depends on how you intend to use this rig. If your bench marks include >250hp and a redline north of 5k, you'd be money and time ahead to re-power with a Chevy or mopar engine.
If keeping the truck all IH is important, then your best bet is to focus your efforts on optimum tuning and fuel delivery to get the most out of what you have. There are literally years worth of reading on topics relating to tuning these engines for best performance contained within the bowels of this tech forum and others like it. There's no sense in me regurgitating all that data that has already been regurgitated fifty times prior. Its out there for you to search through and learn yourself up on. Browse through the IHPA webstore and see what's available. IH parts is the vendor that owns this forum. Explore the fuel injection options, electrical upgrades, so on and so forth. Once your 345 is tuned to the tippy-top from an ignition and fuel system standpoint, you might just be satisfied enough to drive it and enjoy it as it is.
There are rebuild kits available. Performance? Out of an IH engine? You haven't spent much time reading on these forums. IH engines are great when used as originally intended. They were built with longevity and durability in mind. They aren't performance mills. They move heavy loads slowly, all day long, every day of the week, and twice on Sunday. Yes, gains can be made, but they are meager and come with an enormous price tag. A lot depends on how you intend to use this rig. If your bench marks include >250hp and a redline north of 5k, you'd be money and time ahead to re-power with a Chevy or mopar engine.
If keeping the truck all IH is important, then your best bet is to focus your efforts on optimum tuning and fuel delivery to get the most out of what you have. There are literally years worth of reading on topics relating to tuning these engines for best performance contained within the bowels of this tech forum and others like it. There's no sense in me regurgitating all that data that has already been regurgitated fifty times prior. Its out there for you to search through and learn yourself up on. Browse through the IHPA webstore and see what's available. IH parts is the vendor that owns this forum. Explore the fuel injection options, electrical upgrades, so on and so forth. Once your 345 is tuned to the tippy-top from an ignition and fuel system standpoint, you might just be satisfied enough to drive it and enjoy it as it is.