Swap engines, how to advice, please

[cfan10]

I'm wanting to do a swap of my 305 v8 to vortec 5.7, what will I need from donor vehicle besides engine wiring harness, ac compressor.

Will 5.7 bolt up to tranny. I just want better mpg and hp. They also seem to be mostly troublefree. Friend's mechanic will most likey do the job, as he swapped her engine out in a few hours. Mine should be a week, maybe?

Anyone did the swap before advice/troubleshooting possibly pics. Any help will be great, and sincerely appreciated.

Current specs:

84 shortwide
305 v8
Edelbrock 4 barrel carb
True dual exhaust
Auto trans/not sure which one though

Can engine come from any 90's and up 5.7 gm vehicle? Thanks, again.
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[sean1969c10]

The 5.7 Chevy will bolt right up to the 305's transmission. If you have a donor vehicle you may want to use the overdrive trans that will likely be behind the 5.7 Vortec engine.

[cfan10]

Thanks man, but no donor just going to browse salvage yards/craigslist.
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[sean1969c10]

Were you planning on running your carb or going injected?

[Low84]

I think the vortec 350's didn't come out till '96.

[N2TRUX]

Originally Posted by Low84

I think the vortec 350's didn't come out till '96.

That is correct. The 5.7 prior was a TBI that was a DOG.

[cfan10]

Originally Posted by sean1969c10

Were you planning on running your carb or going injected?

Injected. I have a 98 burb with 5.7l and I've fallen in love with it, after getting it back from little bro.
Can distributor or alternator be reused from 305 on 5.7?
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[C15_Sierra]

Your best bet to extract the most mileage would be the 5.7/4L60E (OD tranny) from a donor vehicle, as stated above. I was in the same boat and I ultimately went with a 5.3/4L60E swap in my truck in place of its 305/TH350. That said, my research indicated that there were gonna be similar obstacles to Vortec 350 swap as the 5.3 swap, mainly wiring, fuel system, and AC system. Of course, though, you'd be able to keep your stock exhaust, motor mounts, etc.

I don't know about the computer for the Vortec 350, but the 5.3 was designed to use the 4L60E, so it has tranny controls built in, and you'll be able to plug n play. If you have a 700R4 (mechanical version of a 4L60E) you'll be able to swap and still keep your driveshaft and tranny cooler. I'm not sure if the Vortec 350's have provisions for a TV cable which the 700R4 has because they were designed to use 4L60E's, which eliminated the TV cable.

Next, your fuel system will need an upgrade, because you're running a carb right now. Some LS folks swap tanks to the '87 tank which has an in-tank pump (you'll need to change the pump to a higher flow pump) and a baffle to keep fuel near the pickup. Some others run the carb tank and run an external pump, but you wouldnt be able to drive with less than a 1/4 tank or so before you start starving the pump. You'll also need new lines to deal with the increased pressure. IIRC, Vortec 350's use about 45 or so PSI of pressure in the lines.

AC compressors are different because they use R134a instead of the old-school R-12, so on top of the engine swap, you'll have to retrofit your old system (if it hasn't been done already). That is, if you wanna go that route.

Like I said, many of the above issues are the same as going the LS route, and given that Vortec 350/4L60E combos were going for the same rate as a 5.3/4L60E, I naturally chose the option that gave me the best mileage and power combo. Not to mention, there are simple bolt-ons that will raise the performance level of the stock 5.3.

Hope I didn't scare/overwhelm you...best of luck, and keep us updated!

[sean1969c10]

If you really want to do this my advise is to find a donor truck, there too many little things you'll need to make the swap that will be a pain to have to run to the Boneyard all the time. You'll also know that the engine runs and the trans works before the swap as long as you get a running donor. No the distributor won't interchange and if you use the serpentine system from a Vortec engine the alt won't work either. This swap will more than likely take more than a week to do. Good luck, it will be a nice swap!