I have a 66 Cutlass that has a couple cylinders that are under 90 PSI and one that is at 60 PSI. I have not done the leak down test to see yet, but when I do I expext that I will find a problem with the heads. Now here are my questions:
1. What choice, if any, do I have for after market heads for this engine.
2. My understanding was that the 330 and 350 Rocket were the same block, but after researching it I don't believe that is true so can you tell me if that is true or not?
3. If I can't get heads for it and I have to rebuild these it is going to cost me about $1,000 to do so. Should I just get rid of the 330 since there aren't ANY parts available for it and get a 350 Rocket?
4. I would take any sugestions that you guys might have for me.



1966 Cutlass Supreme - restoring but runs good.
1970 SX455 Convertable - Runs great but needs interior and paint
No Rust on either one

 

OK, I'm not an expert with the small block but let me share a couple things I know and others can add to it. The 330 and 350 blocks are different castings, but the difference is bore. You can swap the crank and heads between the two and many of the external bolt on items interchange. The 330 has a forged steel crank, the 350 a cast iron. The heads will interchange and the 330 used a smaller combustion camber than most, maybe all years of 350 heads. As far as performance parts avalability there are lots of things that interchange. The cam from 330, 350, 400, 403(?), 425 and 455 will fit, intakes from 330, 350, 403 will interchange, headers if you want will be specific for the year/model of cars but again all small blocks would be the same.


If you haven't found the wiki site yet here's a link comparing the small block engines suggesting the best to build:
http://www.oldsmobilewiki.com/index....st_Small_Block

I know there are several guys on the site who have built small blocks, they can add their experience to your thread. John

 

Thank you for all that information. You have been very helpful and I havenow learned that MOST people just don't understand the Oldsmobile engines.
So what engines are interchangable for the 330 Heads?





1966 Cutlass Supreme - restoring but runs good.
1970 SX455 Convertable - Runs great but needs interior and paint
No Rust on either one

 

The 330, 350, and 403 for sure although the 403 uses larger head bolts so the holes need to be drilled out larger. I don't know about the newer 307 engine. Yes, even not all machine shops are familiar with Oldsmobile engines but that's one of the reasons I like them, not everybody has one

 

If you are just trying to get it running good just have the heads you have rebuilt. $1000.00 sounds real high to have a pair of heads gone through unless you are talking including labor. Then its sounds too cheap.

If you use the later heads your are likely to have a bigger chamber and kill the compression and what little bit of power the 330 has.

 

I agree with Richard that just having the heads gone through shouldn't cost $1,000. I had a set of 7a heads done last fall for $360 and that was new guides and some new valves. Machine shops will vary in price but unless you plan to do a lot of porting work you should be less than $500 to have the heads done. Now I would be considering going through the whole engine not just the heads if you could afford it. John

 

Well after reading the website that you posted above I think you are right in that I should keep this setup and just rebuild it. I was thinking that I would let my machine shop rebuild the heads so he can check them and make sure they are straight with no cracks, but he told me that it would cost about $1000. I have never rebuilt heads but I know I can do it with ease. when you had your heads rebuilt and you replaced the guides did you go with hardened seats? My machinest said that he would have to do some modifacation to get the seats upgraded.

 

Also a quick way to see if you have top end or bottom end problem is to squirt some oil in the plug hole. Do you compression check again. If it is the same as before its the heads. If it goes way up then its probably rings.

Good luck....There needs to be more 66's on the road.

 

Thank you .. I have never thought of doing that and it is a great idea.

On a side note, Do you think that I should just take my heads apart and take the bare heads to the machinest to have him go throgh them?

 

You can have hardened seats installed but I've not decided if that's worth it or not. I've had it done on several sets of heads in the past and it shouldn't be a big deal for a machine shop, they will cut out part of the head around the valve seat and put an insert in it's place. For a daily driver I kinda waffle on the need for it though. You may want to post another thread asking the question to see what other people think.

You can also ask if anyone on the site who lives near you (its helpful to post your city/state) can recommend a good machine shop. From what you've said so far I'd consider looking around for someone more familiar with Olds engines...and someone who will give you a better quote for a valve job if that's all you were talking about for the $1,000.

Sorry, I just realized you do have your city/state posted!