mfpm7232

My stock 350 2bbl in my '69 Cutlass seems pretty tired. I recently put in 3.42 gears to wake it up and though it's helped, it's less than what I hoped for. Compression test results ranged from 125 to 147. I plan to do a leakdown test in the spring to tell me where I stand with this engine. I expect that it needs a rebuild.

My plan is to install .030 over high compression pistons, new cam and 4bbl intake/carb. Transmission wuld be rebuilt 350 with shift kit and 2400 stall convertor. Car already has dual exhaust.

My problem is this project would be done over time and I wouldn't be able to drive the car. So I'm thinking to buy a cheap block to rebuild or a cheap runner to drop in while I rebuild my existing 350.

I've come across a 403 shortblock that I can buy for $150-$200 and some #7 heads all together for $250-$300. Would this be a good place to start or should I pass? I'm looking for the engine to make about 300hp tops - nothing too extreme, just something fun for street only. I am aware of the limitations of the 403 bottom end with windowed mains.

I'm in no hurry to start the engine project. As I just stumbled on the 403 for what I think is a good price, I'm wondering if I should grab it while I can.

Thanks,
Mark

oldsmobiledave

If you want a temporary engine to use while you re-do your 350 then just buy a good running small block. For $500 or less you can have an engine you can just drop in & go with no fuss. Sell it off when you are done with it. A 77-79 403 is a fine stand in engine.

captjim

The problem with a temporary runner is that you then have to swap engines twice, incurring some "hidden" costs (oil, coolant, gaskets, etc)
I would leave the running engine alone and find a core to build. SMW 350s are a dime a dozen, or if you want extra cubes, build the 403.

Regarding the 403, IMO the windowed webs are not the flaw, you won't make enough power to matter. The issue is the Siamesed cylinders. The walls are VERY thin, making honing a bit trickier and heat transfer can be a problem.

lemoldsnut

I have a few great running 330 engines that came stock with 320 horsepower. A direct bolt in and way more motor in the end.

Larry
lemoldsnut@aol.com

coppercutlass

Imo I would also wait. Not only is it more work to yank , install , just to yank and install again. Buy a good core build it to suit your needs then when its all good and done install it. Fwiw buy a core trans have it built , get your converter with neccessary stall speed then have it all ready to go . You won't have to worry about dropping the trans later and doing all that. Sbo's are cheap and parts can be found cheap aswell .,slightly used to never installed parts can be found specially if its an over time build.

captjim

Are those 330s pretty high compression?

mfpm7232

Thanks for all the advice. Given I'm in no hurry, I think I'll wait. I was probably reacting to what I thought was a fair price for the 403.

If a rebuild is in my future, any value in sticking with the 350 rather than a 455? Maybe the cost of the core would be cheaper?

captjim

Depends on what you want. For pretty much the same cost, the 455 will give you more power and torque. However, it is not a direct bolt in, but is an easy swap. Also, you will need a cooling system upgrade and will use more fuel. Just depends on your goals and budget, as always.

76olds

Hey Mark, I see your from Ontario. Have you seen the post that another member put up selling engines and parts? I have spoke with him several times now, He has been very helpful with my questions and has given me so much great advice. I'm sure Dennis would help you on some decision making just as he is helping me, along with the awesome advice all the guys here have given myself as well .
Cheers
Eric

olds 307 and 403

Pulling the motor isn't a big deal, pick up the 403. With the #7 heads, it will be around 9 to 1 compression, will run strong, if in good shape. I would pull the pan, change the rear main, other gaskets and maybe the timing chain and gears, if worn. This will give you a chance to inspect the bearings, what cylinders look like etc. A mild can would also add a good gain but there may already be one in there. Then build your 350 at leisure, if it checks out. If not build the 403 for your car. I have got lucky 2 350's, one came with a decent 77 Cutlass for $50, the 350 for $120, nice even decent compression and bottom end looked perfect. I picked up a 403 for $300, fresh rebuild. Make sure your cooling system is in good shape with a 403 and don't run under drive pulleys, I learned the hard way. 455's are gold here in Saskatchewan, 350's are nearly give aways. Same guy who sold me that great running 350 for cheap had a 455 with a bad bottom end, big surprise, I could just tell he probably wanted at least 5 times the price of the 350. 455's start at $700 for J head, low cmpression or knocking junk here.

67 Cutlass Freak

Sounds like the 403 would be a good deal, but still need a little work. From what I'm reading, sounds like your 350 runs OK, but you're looking for a little more performance. I would recommend leaving your 350 in and enjoy your car. Pick up a core 455 and build it up. You can make stupid torque pretty easy with the 455. It will cost just about the same money to build a 455 versus the 350. You will need a different intake and headers, but all your accessories should bolt right up. You should plan your build very carefully for your end use and find a good machine shop that knows the idiosyncrasies of the Olds engine. Trust me, it's better to pay for shipping to a qualified builder, than to blow up your investment because of inferior work. Good luck with whatever route you choose... please keep us posted.