Hey 3rdgen'rs,

My 305 tbi needs repairs, but with over 200k miles on it, i believe the head gaskets are done. Car over heated once, a few years back due to a blown bypass valve, so it pinned the temp gauge momentarily.

Anyway, its tax season, so like most of us, got some money to play.

Want to know from you all that have done what im thinking, whats best for my scenario
1- putting heads, intake, cam, full exhaust, and tuning to get the 305 up to 300hp
2- finding a 96 vortec 350 and swapping in.
Obviously i want to go on the budget side. Im not i terested in putting more than 300 to the vert, just want a cruiser that leaves tires every now and then.

All advise is appreciated. (No LS SWAP, i know its like 5k to do right, i dont wanna do that)

 

The 305 is a boat anchor. Don't sink any money into one. It's a waste. If you don't want to do an LS swap, which I'm not sure is really that expensive, then I would grab a Vortec 350 and go that route.

 

Adding a bunch of new top-end parts to a 200K+ mile 305 short block---especially one that has head gasket problems now---is a recipe for disaster; don't do that.

If an LS swap isn't in the cards, the only other reasonable option is a 350 GM crate motor. Jegs/Summit will have what you need, and other than possibly a flex plate/flywheel/starter issue, will pretty much bolt right in with no problems.

I advise against buying any used 350 unless you know the seller personally so you know the engine's history. A salvage yard engine of that age is very likely to be in the same---or worse---condition than your 305.

 

#2

 

Yep, 96-2000 Vortec 350.

 

Huh? What is a "bypass valve" that causes overheating?

Yup.

 

I'm assuming the heater control valve let go and all the coolant escaped.

 

#2 Vortec 350 all the way. I did it and it makes a world of difference. I did the cheap route and picked up a used one off craigslist for $200 and did a cheap bearing and rings rebuild. Runs like a champ. I spent many years collecting all of the parts though so if you wanna keep it TBI it will cost some dollars.

 

I agree. There are usually a lot of Vortec 5.7 trucks in the u-pull junkyards too. If you can find one that was in an accident and the powertrain wasn't contacted, pretty good bet that it was running good before the crash. 2500 trucks should have 4 bolt mains if you can find one. Keeping it TBI will still be a lot cheaper than an ls swap.

 

x5....or 6? Get a long block from a u-pull it yard for CHEAP. Then add some cam and fuel and there is your ~300hp. Boat builders were using this combo for most of the '00's decade rated from about 320chp to about 350 chp.

 

Vans had the 5.7 until 2002 with metric bolt threads on the motor mounts and bellhousing after 2000.

Some of the larger trucks had the 5.7 until 2004. Like the P30 van and Isuzu/GM cab-over engine trucks.

Worked on a 2015 Kohler generator recently that would not start at my aunts trailer park she recently bought. Uncle told me it had a 350 in it and would spin over but not start. Open the cowling and it had a good old L31 with a victor jr 2bbl intake, a natural gas carb and a marine style small cap HEI distributor. Fixed the mouse chewed ignition control wires. Changed the oil & oil filter, new plugs, wires, cap and rotor and it roared to life. Settled in at 1,800 rpm and sounded good. Probably the easiest way to find one that is in good shape. On LPG or natural gas they run clean and are often rarely run. This one had 25 hours on it. I see them sold cheap from time to time at equipment and surplus auctions.

 

Damn.....^That's^ a fantastic idea. I dig it.