Swapping in an old Chevy 350

So couple months back I busted the block on my K30s 6.2 diesel. Plan was to put in my 70 Cadillac 472 but that put the truck on the back burner. Anyway I was talking to a kid that I sold my 78 K10 to and he said he always wanted to do a manual 6.2 diesel. He ends up offering to swap the 350 out of the k10 even for the broken 6.2.

So now I have this 78 350 to get me by. I'm close to putting it in but just have a nagging feeling that I'm leaving something on the table. Any tweaks that I should do before throwing it in?

Vortec heads and a better intake.

I have a full vortec 350 (junk) with the roller cam and good heads. 75 is what I have in it....

A stock tbi 350 is plenty fun. More is better than less though.

If it was a good runner, replace any leaky seals and drop it in.

BrokenYugo wrote: If it was a good runner, replace any leaky seals and drop it in.

If a sbc stops leaking oil, you better add some...

NickD wrote: Vortec heads and a better intake.

I thought of that but I figure I'd have $300 in a set of heads and intake. I could put that towards the $800 in trans work the 472 needs to drop in.

BrokenYugo wrote: If it was a good runner, replace any leaky seals and drop it in.

That's what I was leaning towards and have done so far just hoping someone would say grab X part for $5 and it'll add 100hp bolt on. Guess I should buy a couple of stickers.

Stampie wrote: That's what I was leaning towards and have done so far just hoping someone would say grab X part for $5 and it'll add 100hp bolt on. Guess I should buy a couple of stickers.

Yeah, unfortunately, being a '78 350, it'll need to be fully addressed throughout to make reasonable power. Compression is too low, heads are open-chambered and poor-flowing, cam is miniscule, and intake and carburetor are designed for emissions.

May be worth throwing a new timing chain set on there while it is out and easy to get to. Maybe the harmonic balancer too if it is questionable.

At a minimum I would put a rear main seal in it, that isn't something you want to discover ten minutes after you get it in and fired up. In reality I would probably install a complete gasket kit (but not the head gaskets, when it comes to the condition of the cylinders ignorance is bliss) and drop the engine in. Since you have plans for a different swap I wouldn't bother with too much more than that, and this way you have a running, usable truck until the caddy plans come together.

SEADave makes a good point on the timing chain, they're almost too cheap not to.

wvumtnbkr wrote:

BrokenYugo wrote: If it was a good runner, replace any leaky seals and drop it in.

If a sbc stops leaking oil, you better add some...

Well yeah, but a slow rear main/oil pan drip is all you need for that, not oozing oil from every possible gasket and coating everything in oil/dirt gunk.

In reply to BrokenYugo:

If you use a 200r4 trans it will bolt to the caddy or chev. I like them better than the 700r4 and you get OD that the 400 doesn't have.

In reply to GTXVette:

But in this case it'll be in a crew cab long bed with 37s. I wouldn't trust it to hold up. Not even sure if my NP205 will bolt up to a 200r4 trans.

I can't imagine a 2004R living long behind a 1970 Cadillac 472 (525ft/lb@3000 SAE gross, even figuring in the SAE net/reality reduction that's 400+ft/lbs) in a 1 ton 4x4 truck.

Smog era 350s are way low compression as already stated. If you can pick up an old roots style blower and run a few lbs of boost that would make that set up kinda fun.