'96 5.7 Vortex for my '71 GMC ?
 

I have been deliberating on what to do about my current engine woes and came across a 5.7 Vortex engine for cheap. Owner claims it runs well so I'm thinking it should be good to overhaul before I replace what I have now. I wan't nothing to do with Injection and recall seeing something about carb intakes being availible for them. Is it worthwhile going this route, or better off going with a Gen1 5.7 ? Plenty of those too but big price difference with them and I don't know squat about the Vortex engines.

Any opinions appreciated :gmc2:

Re: '96 5.7 Vortex for my '71 GMC ?
 

I am far from an expert but have been researching this a lot. All personal preference

One piece rear main seal

Heads are different which is what calls for the unique intake but is what helps with horsepower

If it's in a half ton it's a 2 bolt main

But most everything else interchanges. I think

Re: '96 5.7 Vortex for my '71 GMC ?
 

They call that engine the L31

Re: '96 5.7 Vortex for my '71 GMC ?
 

Thanks Nitis, I don't know much about it yet, the ad doesn't even say what it came out of. But for $250 it would probably be worth rebuilding. Older gen1 350's I've seen have been about $500, and a gen1 454 also $500. All the reman engines now are up to $1800 or so. I'd love to have another 454 but I can imagine what the gas mileage would be like lol. The last 454 I had replaced a blown engine in my Trans Am when I was much younger, drove it hard and put away wet. Oversteared like crazy with the BB but man it was fun :D
Do you know if the flywheels would be different between the older engines and the Vortex ?

Re: '96 5.7 Vortex for my '71 GMC ?
 

Also, just to be the first one to rib you about it, its vortec. Not vortex.


But yea, all you really need is the intake, an HEI distributor, and i wanna say you will need a different water pump.

Re: '96 5.7 Vortex for my '71 GMC ?
 

Re: '96 5.7 Vortex for my '71 GMC ?
 

LMAO.... See, shows how much I know about them :D
What is different with the water pump ?
I've considered just rebuilding the 307, this was kinda interesting... http://www.superchevy.com/how-to/eng...e-performance/
...but in the end involves VorteC heads anyhow.

Where I got the X from lol
http://elmira.craigslist.org/pts/4589600846.html

Re: '96 5.7 Vortex for my '71 GMC ?
 

I have a GMPP crate 330HP/350 which they equip with Vortec heads and a 670 CFM Holley Street Avenger. Here's a link to the GMPP intake sold by Summit, Jegs, etc. I'm attaching the Summit link only because their pictures are better.
http://www.summitracing.com/parts/nal-12366573

Re: '96 5.7 Vortex for my '71 GMC ?
 

I believe it uses the spin on style fan and is reverse flow. Dont quote me on that stuff. I just know that the "easist" way to swap the stuff all over is to get a full sepentine setup from a 89-95 TBI motor. Makes it a one and done setup.

Re: '96 5.7 Vortex for my '71 GMC ?
 

You won't need to change the flywheel, and You can use the distributor, water pump, fan, and all the stock accessories and brackets from your 307, (unless you want to convert to a newer serpentine set up.) You will need a different intake to work with the vortec heads. You will also need an electric fuel pump because there is no provision for a mechanical pump on the l31 block.

Re: '96 5.7 Vortex for my '71 GMC ?
 

The Edlebrock carburated vortec intake costs much less. I picked one up from ebay for $150. Part # 2116.

http://www.summitracing.com/parts/edl-2116

Re: '96 5.7 Vortex for my '71 GMC ?
 

You do need a 1-piece seal style flywheel or flexplate, you cannot reuse your original-the bolts are in a different place on the crankshaft. You should get a hardened drive gear for the distributor due to the roller cam-may can use the one on the Vortec distributor. I do not think you can use the original water pump, the passages in the front of the block look different-may be wrong about that one. Your stock accessories should work fine, but I would use the serpentine setup and later alternator if it was me. I would also leave the fuel injection, but if you must have a carb, you will need an external fuel pump as mentioned.

Re: '96 5.7 Vortex for my '71 GMC ?
 

All good information for me to consider, thanks guys ;)
Makes me think more about going that route and all the extra pieces I'll need to find. The biggest reason I don't want to go FI is all the messing with the harness and VSS sensor for the tranny, I'm staying with my 3OTT for the time being, just can't afford a good 5sp to swap in. That and the shear simplicity of a carb and point ignition. If I break down on the road I can fix it right there without need for specialized tools and code scanners. I am tired of working on the injected vehicles we have here now lol.
I'll dig around some more for a bit.

Re: '96 5.7 Vortex for my '71 GMC ?
 

With what I've learned it's not going to be worth it to go the Vortec route. Even rebuilding my 307 will cost upwards of $2k. So, I have been looking a lot a crate engines from the usual suspects (Jegs, Summit, etc) and also looked at ebay when I came across this place. They give a really good description of what they do and have a 3 year unlimited mileage warranty which seems great. So for a bit over $2300 tax included ....
Reman 350 long block

Re: '96 5.7 Vortex for my '71 GMC ?
 

Had a 96 vortec in another truck a while back. Ran an edelbrock torker 2 intake with a holly carb worked out really well.