340 engine good or bad

[twenty]

I have a 66 skylark with orginal 340 eng in it. was thinking of beefing it up, but have been steered away due to cost. is this true? will it cost thousands to get the engine over 450 horsepower? or should i go with the 455 motor?

ok tomorrow i am going to pick up the 455 motor with turbo trans for $400.00 for both. now i will need to redo everything but the engine is not locked up and has great compression. based on the answers below i think this is the best route.

[pphil]

it will also cost thousands to get there with a 455


just my 2 cents worth

scott

[Joe65SkylarkGS]

I will gladly trade you the 340 for a 68 430 big block?? Complete engine.

[william.ali.kay]

I vote for keeping theoriginal motor and beefing it up along the way.
Its not going to be cheap to get that kind of power no matter which motor you go with.
You could always throw a turbo(or two) on that 340. :)

[jay3000]

It will cost thousands to get there with turbos too.. About 5 of them give or take. But that's cheap for the amount of fun and Bling.. There is no way you could have this much fun with a NA car..

[BUICKRAT]

I will gladly trade you the 340 for a 68 430 big block?? Complete engine.

I have a 340 and an st300 trans I don't need, pm me.

[Nothingface5384]

I say keep it, as it has the same stroke as a buick 350, and the new TA rover heads will bolt up so more options down the road!

you can add a supercharger or turbo for a really nice fun factor

[Stampy]

The 340 was only offered in 66 and 67- its basically an overbored Buick 300. Parts are going to be hard to find for it. In my opinion, it doesn't really make enough power to move a Skylark safely. Gas mileage paired with the ST300 is going to be absolutely dreadful as well, 8-9 MPG when you baby it, worse if you get your foot in it at all.

If you ask me, I'd say go for a transplant. Something bigger, with a better transmission. Doug Ray should be selling a 401 out of a numbers matching 66 GranSport any day now. :rant: (its not his fault, don't shoot the messenger). If I wasn't already knee deep in 455 parts, I'd be lining up for that one for my '66.

[Mr Big]

If it's performance you're after don't waste time and $ on the 340...

[rmstg2]

The 340 was only offered in 66 and 67- its basically an overbored Buick 300. Parts are going to be hard to find for it. In my opinion, it doesn't really make enough power to move a Skylark safely. Gas mileage paired with the ST300 is going to be absolutely dreadful as well, 8-9 MPG when you baby it, worse if you get your foot in it at all.

If you ask me, I'd say go for a transplant. Something bigger, with a better transmission. Doug Ray should be selling a 401 out of a numbers matching 66 GranSport any day now. :rant: (its not his fault, don't shoot the messenger). If I wasn't already knee deep in 455 parts, I'd be lining up for that one for my '66.

I beg to differ with you on the mileage with a 340. I had one in a LaSabre that would get 19 MPG all day long at 65 MPH. Not a hotrod but it would get up to freeway speed with ease. Good engine in my book.

Bob H.

[Opelsauce]

Also wrong is that the 340 is a 300 with a LARGER bore. Not so. The 300 and 340 have the same bore (3.75). As mentioned earlier, the 340 and 350 share a long stroke (3.85) vs the
300's 3.36. Throwing a big block in there would be the cheapest way to go for a quick increase in power.
---Jim

[dynaflow]

...Throwing a big block in there would be the cheapest way to go for a quick increase in power.---Jim

Especially if you did "nothing" to the replacement...

[Mark Demko]

I think the 340 would have plenty of power for a Skylark, hell they put 'em LeSabres. Getting 450 hp outta one isnt going to be easy or cheap:shock:

[Joe65SkylarkGS]

I have a 340 and an st300 trans I don't need, pm me.

Steve New Hampshire is not too far. Let me know the details via PM??

[twenty]

Thanks to all that responded. i think i am going to keep my 340 in the garage (until my wife puts us out) :shock: and get the 455 motor and trans. my mechanic gave me some great pros and cons to doing the transplant. the pros being of course the torque that the 455 offers and the cons being the size and weight. If anyone has any extra parts for the 455 please email me. i am willing to pay for shipping. :dollar:

[twenty]

I will gladly trade you the 340 for a 68 430 big block?? Complete engine.
i am intersted in the trade. i am in chicago. let me know if you are intersested.

[Opelsauce]

As far as weight goes...The 455 is only a little heavier than a 350 chevy. And if you replace that stock intake with something aluminum, it's actually lighter! Engine mounts, headers, etc. are available from TA Perf.
---Jim

[Joe65SkylarkGS]

i am intersted in the trade. i am in chicago. let me know if you are intersested.

Chicago huh? Thats pretty far dude.