Best LO5 Engine Swap

If I had used my original block, and crank, it would have cost me about $300 less (dumb mistakes). I know exactly what is in my engine, as well.

I found another small quirk...the Vortec heads have a higher exhaust port, and the headers I used were designed for the stock LO5 heads. So, the headers moved up a little (about an inch), which is just enough to make the spark plugs a PITA to install. I can only get a socket on 4 of them, and the others must be tightened with an open end or box end wrench. #7 and 8 must be tightened from under the car, and #8 is just above the starter, so I have to reach in from the back.

Found that Jegs is running a bit of a sale on its L31 vortecs right now ($1500 shipped)...

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I know there are some needed changes vs. the LO5 but they seem doable (new intake manifold for one, exhaust manifolds too..) but still, someone tell me this is an awful idea....

Be careful installing a Vortec engine. I would suggest that you do NOT use a carb plate to lift the engine into the car. Find another lift point(s). The intake manifold gaskets are subject to leaking if disturbed. The best gasket recommended is the FP 980000. Others are subject to leaking initially or in the future.  You can also warp the intake manifold by lifting the engine with it.

I put small block shorty headers on an engine with Vortec heads, and had to remove the starter to tighten the #8 plug (installed plugs after installing headers). The 4 rear plugs were a PITA. Make sure you get headers/manifolds that allow clearance for the plugs.

You will have to rig a mount for the linkage unless you use the $400 GM intake manifold for the TBI. If you choose a 4 barrel TBI system the bracket will need modification. Make sure you get it right, or you can have major issues with other parts, like the trans.

The stock Vortec water pump is shorter than the LO5 water pump, and if you choose the Vortec pump, you need a 1/4 to 3/8 inch spacer behind the pump, if you want to use the LO5 FEAD. The Stock Vortec water pump pulley is a larger diameter than the LO5 pulley, and the belt must be 1 inch longer. The pulleys are not interchangeable between the pumps. You can use the LO5 pump, pulley,  and the LO5 FEAD.

The flex plate is the same for both engines.

If you have any other issues, feel free to contact me.

Thanks Fred - I looked around the garage last night and decided I should land a couple of planes before I pull the wagon apart, but this seems like a good way forward. I suppose in 'ideal land' the performance of the vortec 350 is pretty close to the LT1.

There was a suggestion on another forum that the LT1 exhaust manifolds would be a good match to the Vortec, with one additional hole drilled. Sound plausible or even desirable to anyone?

Waste. Better off just getting real headers.

I thought of real headers, but $$$ stood in the way, and I had the shorties on hand with the rest of the exhaust system.

I am thinking of installing an Olds engine into my wagon instead of a Chevy engine, my 305 is running ok for now (227k miles) but I would like to upgrade to a bigger one. I was originally thinking a 307 but after some research I am better off with a 350, 403 or 455 Olds. I was reading through the posts and saw OCC6.6 and Fred did something besides an LS. There are no Olds engines in those sizes newer than 1980, and I would like to keep it fuel injected. Anyone have some advice on what needs done to make this work?

You could put a large Olds engine in the car, use the 4bbl intake, and use a Holley, or Fitec throttle body injection system. You need to use one that can control the spark, because you cannot change the distributor.