Vortec Engine Rebuild Or Not L31 5.7 L30 5.0
The reason I am writing this article is to let people know a few things about vortec heads and engines. We all know the vortec is a great head and make good power in performance rebuilds. So many of us want to rebuild our truck engines and make them more powerful. Many think its easy and does not cost much but there is one thing to consider even for the cost of rebuild you can buy a new engine straight from GM with all new parts.
Now the L30 305 is the cheapest it only cost $1600 brand new. You will be hard to find a good used engine for this price. The L31 is not much more at $2000 bucks all new and never run with all the bells and whistles. This includes the roller cam and good vortec heads that are new. For this price you will surely spend more on the rebuild than this motor.
Why so much
Why is the rebuild so much. Well aside from an expensive ring package the engine is not more than any other engine to build. But here is one problem you may not think of. The is a good one and will go 200K miles before it fails with heads prone to cracking and lots of heavy use over the 200K miles in its lifespan.
You will need to redo the heads at the machine shop surely it will need some work. Now that is going to cost some bucks. figure pistons and rings bearings and all the other parts like new water pump and starter you will have spent at least 2k if not a lot more. Now with a brand new engine you know your going to get the 200K miles the rebuild may not be so lucky. Once you figure turning the crank and other things might as well not even look at the rebuild and just buy a new one outright.
Guess what its cheaper new
Most of us would not think the engine brand new from gm would be affordable but it is and more than that its a good one. There other engines are ok as well but this one has many feature today hotrod drivers are looking for good heads roller cam and 400 hp potential. Right out of the box. Now you may need a few upgrades to get there the heads need some machine work or different beehive springs but worth every bit as they are bolt on and work great. Using the LT4 hot Cam and a few computer upgrades that 400 hp is a real goal. with a carb and a good intake manifold and long tube headers it might make a few extra ponies in the process.
With all that said its just better to get a new one and move on. Sell the old one to someone that is not aware of how cheap they are new. A good rebuild is not even as good unless all your parts come from GM.
What can be done
Now leave the engine sealed up upgrade to the lt4 hot cam with new springs install a small turbo kit to make 6-8 psi and you can up that 255 hp stock engine to 500+. You will be very happy its a brand new motor you can rely on and have lots of fun with. A small amount of boost goes a long way toward making a regular car a rocket ship. Even in a heavy truck a little boost turn it from weak on hills to hauling machine. This is also just about the cheapest option in performance for these engines. A small amount of boost can also make these engine very fast.
Here are a few links to jegs for the engines they offer free shipping and good service.
This one is not a vortec but still a good start over some rebuild cost. For major performance upgrade this one will need new heads to really sing.