305 Vortec to 335 stroker

Tachyon said:

I don't think you'll find a lot on this because the cost and effort don't justify the power results. Also the 305 block has some inherent design weaknesses that are hard to ignore.

If you want to do this just for fun and to try something different, go for it. But if you're looking for the best bang for your buck power, cost, and reliability wise, this isn't the way to go. A 350 swap will definitely be a better choice in that regard. A crate motor is one option, yes, but you can also go with a decent used block and a little machine work.

Click to expand...

I've never heard that a 305 2 bolt block is inherently weaker then any 2 bolt 350 block. ?? The 305 vortec heads can be a big limiting factor though.

got the 383 short block from Summit Racing, 9:1 CR, can't remember the cam specs, the guys at summit reviewed what I was building and recommended, didn't have mess with the fuel delivery outside the tune from black bear. the initial tune had a flat spot just off idle, but a call to black bear with the description of issue and they reprogrammed it perfect. was very happy with it. had the granny gear manual trans, so redlining and speed shifting was not so good, would have been way more fun with an automatic, but would light up the 36" BFGs in second...stripped teeth off the rear 1/2 ton ring gear & pinion once applying too much power to get out of a deep hole, but that's a pilot error story...anyway a lot of power there

Piratehunter said:

I bought a crate 383 short block to replace the 350 in my 87 k1500. Used the 350 top end so all induction was stock, new valve/springs, long tube headers, and new chip to cover engine, gearing, and tire size changes. It was a hill climbing, tow anything, torque monster. Would go that route again

Click to expand...

crate short block? im not getting that logic, or lack of. how was the compression ratio to be adjusted>?

Redneckgeriatric said:

crate short block? im not getting that logic, or lack of. how was the compression ratio to be adjusted>?

Click to expand...

It's 9:1cr so it's not a zero decked 10:1 quench build. It's a safe build for a truck that may pull some weight. You can move the cr around a bit with head gasket thickness.

Supercharged111 said:

305 has a smaller bore and doesn't have the breathing potential of a 350. How is stroking a 305 cheaper than. 350?

Click to expand...

I understand its breathing limitations. It would be cheaper simply because I already have the 305 and wouldn’t have to buy a crate, as I’m not too fond of the idea of getting a used 350. I was just curious if anyone has done this with a vortec or not. I know it won’t get nearly the the same power I would out of a 350 but I’m not looking to build a drag truck or anything like that, just want something more comparable to a modern truck’s power. I also find some personal value in keeping the original engine, as long as it makes sense and makes enough power for me.

1997 said:

interesting project.
That's what makes the old stuff fun, thinking outside the box.
383 imo, would be the obvious choice, why are you thinking stroker 305?

Click to expand...

I’m thinking stroker 305 simply because I would value keeping the original engine as long as it makes sense. The 305 is running fine as of now, and only has 70k miles but this will be a long term work truck for me so I know I will eventually want to have the motor rebuilt just to ensure its reliability. When I do, I want to know I’m doing the right thing. If that means swapping to a crate 350 then so be it, but if the 305 can make enough reliable power, I would prefer that.

cngodfather said:

The absolute only reason to do it is because it is very rare and that you can say that you did it. Financially, it is a bad idea. It will be costly to do it correctly. Would be cool though. 305’s. Like to spin fast to make power. Stroker engines exert a lot of stress on the pistons and rods. Therefore you cannot spin them as fast. Therefore these situations are fighting each other. It can be done, but it won’t be cheap.

Click to expand...

Thanks for the response. So I’m only asking out of complete ignorance, but could you fill me in on why 305s specifically like to spin fast and strokers don’t necessarily like to?

Hipster said:

305 stroker pistons are more costly then 350 pistons. Parts and labor, machine work etc. You can't build one for what a vortec crate costs.

Click to expand...

If that ends up being true, then I would definitely end up doing the swap, I’m not just trying to throw away money. The crate engine I’m interested in cost a little under 3k plus, sense I don’t have the necessary equipment, cost for a shop to install. So do you think having a shop do a rebuild + stroker in my current 305 would exceed that?

oh hell yes. Anytime a shop does anything ur gonna pay out the ass....

A new 350 crate is $2200 to your door. I doubt a 305 stroker would be appreciably, if any, less.