jag1886

1. I read about people putting 350 heads on 330's, the question I have is what needs do be done if anything about the bank angles being different, I'm thinking the pushrod holes would be off?

2. I've also read many places that you can over bore a 330 by .119 and use 350 pistons. Anyone have any personal experience doing this? I've also read about someone boring .063 over and using a set of 360 Mopar pistons.

3. If no ones answers to these questions how would??

f-85

Yes its no problem to use 350 heads on a 330. But if you still have your 1-4s. There is no reason to swap. They are all around the same flow wise 1-7a. But the 1-4s have a smaller chaber.

All you have to do to use the later heads is drill out the pushrod holes.

Redog

I would also like to know about the piston question, for future referance

InfoJunkie

If you want more cubes in a SBO get a 350 or better yet a 403. Swapping pistons usually involves machining.

jag1886

This brings us to question # 4 why do people say that the #2 heads like have are inferior? I have never seen anyone elaborate on this.

InfoJunkie

They aren't inferior just made to do a different job. Most people look for big flow numbers that give power at high rpm. Smaller flow numbers by smaller runners and valves more bottom end torque and with proper tuning better milage. Common thinking is if it doesn't increase power it's junk.
JMO

jag1886

Thanks that's useful information. This car is totally intact and I'd like to keep it that way. I am looking for an honest 300-350HP which I don't think is a reach for this motor.

jag1886

I have an all matching # car and I don't subscribe to the take it out and throw it away theory.
What's the difference in spending a little more for machining instead of buy a completely new junk engine to start with.

Run to Rund

For that much HP you need good flowing heads, big camshaft, modern build. Sonic test the block before boring it very far. 4" is probably safe and you can deck it about .050" and use 350 Chevy high perf/race pistons, bush the rods for .927" pins. Mopar pins are bigger diameter than stock so you would have to bore out the rods. Don't use old school heavy pistons for 325+ real HP as you will be going up to about 6500 rpm. I would recommend a solid lifter cam and ported heads. As an alternative: Look at the W31. It had a big hydraulic cam, 2" intake valves, 350 cid. You could mimic it.

InfoJunkie

I didn't say anything about throwing it away. 330's are hard to find as they were only built for 4 years , 350's for 20yrs. It sounded to me that you were looking for more performance rather than having a block with too much cylinder wear. Keep the original engine original.

captjim

I agree with most of that, but why bush the rods? Just cut the crank .025 and use brand new 6" SBC after market rods. That way he could use cheaper SBC race rod bearings. Mahle makes a great piston for the $ and comes with a quality ring pack. Head work will definitely be required, but we are only talking about 1 hp/ci

Run to Rund

true, and the aftermarket rods will be stronger for a good price.

Redog

I would still like the answer to the question about which pistons to use on a rebuild.

For that day that my 330 needs to be rebuilt

captjim

Too vague, there are several options depending on budget and goals. Bore to 350 SBC and use a 1.550/1.560 p/h and mill .050 to make up the difference like Rund suggested. Recondition and bush stock rods or use after market SBC rods.

Bore to 4.087 and use 350 SBO pistons and stock rods.

330 pistons, if available.

302 SBF piston has a 1.605 p/h and a .912 pin

Custom pistons.

and on and on....

Run to Rund

You start with a sonic test on the block, not just a couple points per cylinder, but thorough mapping to see how far is safe for the boring out.
Then, you need a clear idea of your goals in terms of HP, how much if any street use, etc. When you posted that you wanted 300-350 HP, that took you out of the realm of a stock-type tractor engine rebuild and into the high performance world. Several of us can help you get there, but don't expect us to agree on everything. Furthermore, if you then go to an ordinary rebuilder, you may not get good results. We can probably help you find a good rebuilder who knows Olds engines somewhere near where you live. That is part of the equation.

InfoJunkie

Close to that day would be the time to figure out what parts to use. New parts are constantly being made and current parts being discontinued. With some simple math and specs for parts available(pistons & rods) just find a combo that fits a safe bore and a block deck height the same as your 330. As said before there are different combos and different opinions about what to use. I am assuming the math has been done.

Redog

OK

I just like to have the options totally ava to me.

I'm buying parts to rebuild my Alero's engine, slowly but surely. I currently have a bottom end that needs to be rebuilt, narrowed SBC rods, and a street/strip cam on the way. Going to be buying diamond forged pistons sometime next year. Also want the double roller TC

I already have a decent set of P&P heads (milled .020 raising the CR from 9.5 to 9.7) on the car along with port matched upper and lower manifolds, full exhaust, cold air intake, and working on programing now