Your question is vague. If you mean how much as it sits, 290hp. If you mean potential, it all depends on what you are willing to do to it. If you are just looking for a foundation to build a whole engine from, this is not a very good choice as it is a lot of money to spend on a block. You could replace every part in that engine and get something better, but then you can do that with a junkyard truck block and the core will only set you back around $100. I'll ask you the same thing I ask everyone else: What is the intended application and what parameters are you trying to meet?(budget, fuel economy, quarter mile time, daily or occasional driver, car set up for handling or for drag strip performance or as a good all-rounder, etc.) If you just want the car to run for plenty of miles this engine is fine. A typical G body with an engine like this will probably run mid 14's given proper gearing.
Analyzing the engine: The heads are probably the late 80's cop car castings Gm used on the old 300hp crate engine and not well suited to performance use. It would not be cost effective to properly modify them when compared to the same money spent on better heads to start with.
The compression is low so that it will run fine on dog piss, but again this is not good from a performance standpoint. It limits your cam selection, and the cast pistons limit you from running Nitrous or a forced induction setup with high boost.
The powdered metal rods are not as good as most aftermarket forged rods.
The cam is tame and streetable, but would need to be changed in a high RPM application
The cast crank will not survive high RPMs for too long or nitrous or forced induction with real boost.
The Performer intake is well suited to this long block, but will be a cork to a high RPM engine.
Remember: RPMs make horsepower and a basic 350 crank, rods and pistons does not like to be revved too hard too often. Neither will the oiling system. Horsepower is not a measurable force in and of itself. It is a mathematical function derived from a given torque output at a given RPM. So, any engine revved high enough can make horsepower--if it has proper airflow and the reciprocating assembly holds together. Horsepower basically says that if you increase the sheer number of power producing events in a given span of time you will increase the work done due to speed. This is why a Honda B16 can make 160 hp and 110 ft lbs of torque. It does it at around 8,000 rpm's ( almost 9k redline). However, a stock B16B2 in a 2000 Civic Si is still slower than a stock SR20DE in an old 1993 Sentra SE-R with 140hp. Both weigh about the same ( Civic may be lighter) both are geared properly. The Nissan has the more usable power curve overall and is faster in the 1/4. ( 99-00 Civic Si runs about a 16.1, Sentra around a 15.5-15.8--depending on who you ask) The Honda is also irritating day to day because you have to rev the wee out of it to get it to do anything because it is so soggy on the bottom end. It's a fun engine to wind out in a lightweight car, but most of the time people don't drive at 8,000 RPM's and it has little power where it is needed most. ( I chose the B16B2 because it is the most extreme example of a production hp engine most of us may have encountered.) The other example would be an S2000 vs a 5.0 Mustang. Both have similar HP but a low option 5 speed Mustang is faster in the 1/4 despite not having a 9k rpm Redline.
The Crate 350 in the ad is designed for low to mid RPM torque and the components contained in it are chosen for that purpose. My advice is to forget about horsepower and concentrate on a good torque curve. Maximize the area under the curve and gear the car accordingly. After all, peak numbers are irrelevant if they are not backed up with similar numbers elsewhere in the curve. Unless you have a CVT, you will not continuously run the engine at either the torque or horsepower peak.
Finally, you can do better than this for the money if you plan well and know how to shop. You can also do worse if you buy mismatched components.
Analyzing the engine: The heads are probably the late 80's cop car castings Gm used on the old 300hp crate engine and not well suited to performance use. It would not be cost effective to properly modify them when compared to the same money spent on better heads to start with.
The compression is low so that it will run fine on dog piss, but again this is not good from a performance standpoint. It limits your cam selection, and the cast pistons limit you from running Nitrous or a forced induction setup with high boost.
The powdered metal rods are not as good as most aftermarket forged rods.
The cam is tame and streetable, but would need to be changed in a high RPM application
The cast crank will not survive high RPMs for too long or nitrous or forced induction with real boost.
The Performer intake is well suited to this long block, but will be a cork to a high RPM engine.
Remember: RPMs make horsepower and a basic 350 crank, rods and pistons does not like to be revved too hard too often. Neither will the oiling system. Horsepower is not a measurable force in and of itself. It is a mathematical function derived from a given torque output at a given RPM. So, any engine revved high enough can make horsepower--if it has proper airflow and the reciprocating assembly holds together. Horsepower basically says that if you increase the sheer number of power producing events in a given span of time you will increase the work done due to speed. This is why a Honda B16 can make 160 hp and 110 ft lbs of torque. It does it at around 8,000 rpm's ( almost 9k redline). However, a stock B16B2 in a 2000 Civic Si is still slower than a stock SR20DE in an old 1993 Sentra SE-R with 140hp. Both weigh about the same ( Civic may be lighter) both are geared properly. The Nissan has the more usable power curve overall and is faster in the 1/4. ( 99-00 Civic Si runs about a 16.1, Sentra around a 15.5-15.8--depending on who you ask) The Honda is also irritating day to day because you have to rev the wee out of it to get it to do anything because it is so soggy on the bottom end. It's a fun engine to wind out in a lightweight car, but most of the time people don't drive at 8,000 RPM's and it has little power where it is needed most. ( I chose the B16B2 because it is the most extreme example of a production hp engine most of us may have encountered.) The other example would be an S2000 vs a 5.0 Mustang. Both have similar HP but a low option 5 speed Mustang is faster in the 1/4 despite not having a 9k rpm Redline.
The Crate 350 in the ad is designed for low to mid RPM torque and the components contained in it are chosen for that purpose. My advice is to forget about horsepower and concentrate on a good torque curve. Maximize the area under the curve and gear the car accordingly. After all, peak numbers are irrelevant if they are not backed up with similar numbers elsewhere in the curve. Unless you have a CVT, you will not continuously run the engine at either the torque or horsepower peak.
Finally, you can do better than this for the money if you plan well and know how to shop. You can also do worse if you buy mismatched components.
