damenbrazen

Hello to everyone. This is my first post. With all the time on my hands due to the pandemic job losses, I pulled apart my motor, which has been making a nasty metallic chatter/rapping noise at about 2300 under light load for the last 500 miles or so. Sounded like a cracked piston or broken piston rings.

The car is a 1967 Cutlass Supreme Holiday coupe with the high compression 330, A/C, Jetaway 2 speed auto, 3.08 open rear gear, Edelbrock 7111 Performer RPM intake and the smaller Edelbrock AFB type carb. HEI ignition from a 1979 or so Firebird. 103,000 original miles, I repainted it in 2001.





Stock heads were rebuilt 5,000 miles ago due to leaky valve stem seals causing a rough idle.

Half the main and rod journals are out of spec, all the bores are definitely out. This caught my eye: pitting in the walls of a couple of cylinders, something I haven't seen before.



Cyl 6 pitting in wall, w/scaling

Cyl 6 pitting in wall full view w/scuffing, scaling


Explains the mysterious “head gasket leak” I’ve been chasing for the last three years. Strangely never had coolant in the oil or exhaust, but did have a gurgling water heater core and weeping at the thermostat and coolant fittings.

So instead of doing a stock rebuild of the 330, looks like I’ll have to replace, at the very least, the short block. But since everything is out, maybe now is the time to build a nice little motor. I'm a little stuck as to what to do next.

I use the car mainly around town/freeway and for the occasional long 350 mile haul to see the folks, so drivebility with A/C and PB in hot weather is the biggest concern. I plan on keeping the two-speed switch-pitch auto and would like good efficiency, so torque down low would be the goal.

I’m looking to spend up to $3,500. $3,500 times “we found something you should look at” will probably equal $5,000 so I’m ready to consider that, too.

Questions time:

I figure 3 options:

Use a rebuilt stock 350 short block with an “RV” cam swap and the 330 heads, maybe mild port work. $1500
Build a long block 350 with mild port work and the cam swap. $3,500
Build a budget stroker 350 with more head work and cam, using the ’67 forged steel crank. $4,500-up

I’d like to keep iron heads because of the look and the accessory brackets/fuel pump, and looking for TQ down low not HP on high.

I’m looking for feedback on the possibilities given the budget, the use of the 330 heads vs. 350 heads, if the later 350 blocks are worth a damn, recommendations on camshaft selection, or stroker parts combos, things I haven’t considered, lucky lottery numbers, tum-key solutions.

About the different bolt pattern of the pre-1968 crank. If I use a 350 crank, can I use the 1967 switch-pitch TC with a post-1967 flex plate?

Also I need a machinist around Los Angeles who knows Oldsmobiles, so maybe it’s worth it to talk to Bernard Mondello in Corona? I’m just afraid he’s $$$. The guy I used for the heads set the valve stems at slightly different heights (my Chebbie guy). And where is there a classic salvage yard in SoCal? All the ones I used to go to In Sun Valley are gone! After a could finally afford a newer car, I kind of didn't need to go so often...

Lots of questions, thank you in advance for any advice.

olds 307 and 403

You might get lucky and find a good Olds 350, up to 76 are the best. The 77 to 80 are the windowed main blocks. If a 77 to 80 can be heard run and oil pressure gauge put on. They have more bottom issues and horrible, crank prone heads. Any 73 to 80 motor that can be heard running and an oil pressure gauge on might just need new gaskets and go. I have picked up 3 orginal 73 and two 76, well this 73 was probably a 2bbl so it had a 83 307 intake and carb on it, non CCC till 85 in Canada. Good compression and oil pressure. Shim head gaskets and nylon cam gears when I swapped heads and unmarked bearings in great shape say original. With your 330 heads, any stock 76 to 80 350 will yield high 8.xx to 9 to 1 compression depending on your head CC. Mine #6 heads were 62cc with .028" head gaskets put me right at 9 to 1 with a factory short block. Also consider a TH350 as the much better first gear and go with a 2000+ stall converter, it will make it night and day better.

Oldcoyote

Does the 330 have the sought after N crank?

Fun71

No, all 330s had forged steel cranks, not nodular cast iron cranks.

jmos4

Hi,

A 330 has a Forged crank, different timing marks and different flex plate.

Your heads should work on a later 350, though depending upon cam bank angle 45 or 39 you may have to open up the pushrod holes..

I was in your position a few years ago and depending upon your goals 3500-5000 grand budget might not be enough.

You might want to look for someone doing a LS or BBO conversion and luck out and get a decent SBO, seen a few for sale under a grand.

If you do rebuild one or get into swapping a cam talk to Cutlassfi/Mark Remmel as he can point you in the right direction.

Good luck,

damenbrazen

Thank you Olds 307 and 403 for the suggestions on the early 350 blocks and how to spot an unmolested one. One of the very first things I did when I got the Cutty was to replace the timing chain and gears. Sure enough, when I pulled the engine this last time, I recovered a few nylon chunks from the oil pan. Just like 70's Ford small blocks. My heads are supposed to be 64cc, I'll have to borrow a graduated cylinder and glass plate from a friend to check. I figure I can order a Cometic gasket in the right thickness to get me to 9.0:1, the highest I could probably go on pump gas with iron heads and a carb.

jmos4, thanks for your info on the cam bank angle. My 330 is 45 degree. Does that mean I simply open up the pushrod holes to a larger diameter, or do I simply need to clearance or egg out the top and bottom holes?

Currently searching for that early 350 to rebuild!

jmos4

Hi again,

I have never done a head swap between a 45 degree cam bank to a 39 degree, but I would imagine you need to clearance the holes/slots toward the cam and valves not width as unless your upgrading the pushrod diameter, but never seen any mention of it in other posts

Good luck again,