My 1970 Oldsmobile Cutlass S

Olds 307 and 403

Active member
Oct 4, 2018
339
101
43
Melville, Saskatchewan
How it currently looks. 9 to 1 Olds 350 214/214 cam/TH350C/2.78 open type O rear.
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I have been fogging the back to cylinders with this.20190817_162452.jpg
#7 and #8 were 110 psi vs 150 to 155 for the other 6. I gained 15 psi on 8, maybe 5 on #7. No real gain this 3rd time but will use up the can in those cylinders. Either way the 350 will be going in the 88 CSC with the 2300 stall lock up torque converter and maybe the modded governor, should be around 5000 rpm shift points. Also putting the Performer intake back on, 1" open spacer and putting the hot air choke back on, will convert the 260 to electric. Along with a new A/C compressor, condensor, receiver dryer and maybe an evaporator, want working A/C again . Want a fun car to drive and hoping for 20 mpg while I build the 70S. It will adopt the 260 so it can move around. I plan on picking up the longer main studs and a girdle this fall and get the 403 block to the machine shop. Already have cam bearings, just main bearings to assemble the bottom end, will probably get them and some roller lifters from Cutlassefi. I am waffling about using iron heads but already have a set of ported #6 heads with 2"/1.625" valves and filled crossovers. The chambers do need to be enlarged a bunch and I would add new positive seals and springs to match the roller cam. Procomp heads are tempting as well. I was also waffling between a TH350C or a 4L80E. I do have a 2004R that lost 3rd and 4th due to my daughter running it low on fluid. I think building my extra half wrecked 2004R is better than paying $500+ for a questionable 4L80E core that might need rebuilt anyways. I actually HATE it's gear ratios, none are ideal, just like the strength idea of the 4L80E. If I splurge for the billet forward drum, new sun shell, billet 10 vane pump, shift kit, servo, sheet metal pan and big rebuild kit from CK Performance, I will rebuild the 2004R myself and should hold up fine, don't trust the local trans shop. I may go with Dr Dan's 2004R converter he runs, around 2800 stall. I have CK's big manual to help me do this. It may take some time, I do have a somewhat working non functional lockup TH350C, don't want to rush the 2004R build. Then I can run 3.90 gears, 1900 rpm at 60, 2200 rpm at 70 mph with the planned 275/60R15 tires, perfect cruising rpm. What can I say, want the acceleration to be like a sledgehammer and not screaming on the highway. New cars have spoiled me, steep first gear and great OD, want that for my 70S. Plan to have the short block together by Summer but bodywork, paint, orginal Sherwood Green, grills and maybe tail lights are a high priority as well. Also considering the AEM infinity on multipoint EFI but may just use the 750 Street Demon or send my extra Qjet to Everyday Performance. I would also add a wideband, planning on the Stainless Chinese headers and 2.5" dual exhaust to finish it out.
 
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Olds 307 and 403

Active member
Oct 4, 2018
339
101
43
Melville, Saskatchewan
The 403 will be 4.390" bore, .043" top ring, 1.5, 3mm ring pack 550 gram Venolia custom forged pistons, 6" Scat SBC 2" journal rods, 3.5" stroker 330 crank for 424 ci. Thinking 9.6 to 1 and fairly aggressive roller cam to run with a decent timing curve on 91 non ethanol octane is the plan.
 

Olds 307 and 403

Active member
Oct 4, 2018
339
101
43
Melville, Saskatchewan
I have been able to get the washer working so I ran a separate toggle switch and cut a hole in my washer bottle to fit the 96 Toyota Tercel washer motor in. I had it from the cracked washer bottle I had. I see Canadian Tire has a very similar universal pump if it ever dies. It works great, wired to engine run power in the fuse box. I bought another can of the Kleenflo Combustion Chamber Cleaner to try to get more from #7 and #8 cylinders on the 350. The trans is slipping pretty bad, can feel it going in and out of gear at low speeds. I will pickup a regular used TH350, probably a Jegs high stall, probably the 2300 to 2700 stall over the 2000 to 2300 stall, my cam won't be mild and a Transgo shift kit to help it live. I already have a modded governor, will probably try the Transgo springs to raise the 1-2 shift above 4750 rpm. I just need it to last till I can build 2004R core, 2 grand in parts alone to survive. It should be liveable with 2.78 gears and 275/60R15 tires on the highway. I will probably use a pair of my 215/75R14 tires on the front, currently 205/75R14. I plan using the Chinese stainless long tube headers, super cheap and well made, they hang low on a 350. I have very good ground clearance but a 1/2" helps. I need to send Cutlassefi some money next week to get back my Performer intake, too bad he never got to Dyno it against a RPM along with some roller lifters and longer Ford main studs. Then I will just need a 5 main Halo to send the block to the machine shop. I picked up Clevite cam bearings for $10 off Amazon. Of course we spent $1800 on furniture this week and I have to pay off by April. I will have Income Tax and a bonus through work. Of course the bonus went way down the first year I started working. Ironically the fuel department is the only department making any amount of money, I am a fuel truck driver. As usual life gets in the way of getting these cars done. I have decided to not put the 260 back in this car, motivation to finally get this motor done. The only things body wise I plan on next year are the wrecked grills, plan on used Cutlass S grills. The reproduction S grills new are $100 more than the 442 grills. Also I want the cracked windshield replaced. Ironically I was quoted $100 cheaper than the 96 Toyota Tercel. They did a good job but the other shop is ran by a retired body guy and he just did a 68 Cutlass convertible. He is usually cheaper, wants to stay busy. As much as the paint looks like crap on the 70, I still get constant nice ride compliments. So I can live one more year as it looks. I really want a car that annihilates the tires with the gas floored. Hell that should be all of our cars main focus.