Engine swap - issues with power
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Olds 307 and 403
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Pretty sure A body full length headers will fit. Don't buy Flowtech, thin flanges and rust quickly. I know a few have had issues with Hedman and Hooker for fit lately. The full length Chinese stainless headers are well made but hang low. The Sanderson and Thornton shorties are a good option. Thornton also makes a dual exhaust manifold that is slightly larger.
Well, all Napa had were AC Delco’s 43S
Should I hold out for the NGK 45XR ? As Recommended?
Olds 307 and 403
Well-known member
Yes the engine is a 1972, 350. But the car is a 1981 Olds 98 Regency. Was told, it was rebuilt and used at the circle track for a couple races. I bought the whole engine used for $1,000 in Florida.
Whats the difference between an olds 350 and a chevy 350? When I went to Napa looking for a new cap and rotor, the red cap I took in for comparison, I was told was from a chevy distributor. I’ve also had issues buying oil filters and air filters from Carquest that don’t fit?
So I really have no exact idea what I have, nor what kind of cam or pistons they installed, etc..
The distributor wiring diagrams online match that of a 1980’s Olds 307 Cutlass. But the timing indicator tab doesn't match the diagrams. 0 degrees starts on the right side of the balancer if you’re looking at the engine from the front and goes to the left towards 20 degrees. But online diagrams are the opposite view? My tabs are behind the balancer, but online diagrams show the tabs in front of the balancer? But with the digital timing light it all makes sense what I’m seeing.
Olds 307 and 403
Well-known member
An Olds 350 is a totally different design, very similar other than bore size to the Oldsmobile designed short deck or small block V8's, 260 through 403. The 400, 425 and 455 tall deck or big block Oldsmobile V8's are very similar but have 3" mains, 1.3" taller deck requiring a wider intake manifold. The cap and rotor are the only thing that will interchange. But your 72 motor had a different points cap and rotor factory. Just order a cap and rotor for a 307. You can use a 307 oil filter but it is small. I usually use the Wix 51258 or Napa Gold 1258 or Hastings LF222 oil filters. Good chance either the big dish factory pistons were used with new rings or the short on height big dish replacement pistons were used. If that is the case, you have 8 to 1 compression or less. I would add at least 5, maybe 8 degrees more timing. Yes, the 0 is at the bottom, the 20 is at the top. Many things are different on the Olds V8 vs a chevy V8. You can actually fit more Ford parts on your Olds V8 than chevy parts.
I took a plug out, it was clean. AC Delco R45S it was gapped tighter than .040 but more than .035
I took all of them out regapped the
To .035 then realized I had changed them when I installed the engine. I changed the wires. Set the timing again, higher to 34 degrees total at 3,000 rpms.
Then I drive it 100 miles tonight most of it was 70-75mph. Got to my destination did some driving around town and then the engine died all at once. I coasted to the median. It would crank but not sputter at all. I checked the carb and with the key off the jets were dripping fuel. It was flooded. I stuffed a screwdriver in to hold the primaries open while I cranked and I got it started. Turned it off, put everything back together, started it again and drove to my destination a few miles away. When I turned it off there, and tried starting it would crank but not sputter. So i’m not sure what do with the fuel regulator settings. It was on 4.5 (1-5). What should the pressure be?
Olds 307 and 403
Well-known member
Your fuel pressure sounds about right. Do you have a fuel filter before the carb? I would try another 2 to 4 degrees of timing.
Ok. I have one of those plastic see thru fuel filters between the tank and the fuel pump. So, before the fuel pump, but right next to it. The gas tank is new (couple years old).
There was also a carb stutter on this drive each time I started from a stop. Maybe that was the hint that it was getting too much fuel?
Olds 307 and 403
Well-known member
It could be, try turning down the regulator a bit. A custom tuned Qjet would be my choice on this motor. Does it have an adapter for the Holley on the stock intake?
It had a computer controlled quadrajet originally with all the smog crap that didnt work right on the 307.
Im not sure if I have that carb still to turn it in for a tune job. I also have an Edelbrock carb somewhere that I’ve used on this 350. But this Holley has no adapter, just the thick tab gasket. It does have an external lever and adjustment spring on the primary bowl which has something to do with an extra squirt to get going?
Olds 307 and 403
Well-known member
Yeah, that Qjet won't work, different inside than the older Qjet's. Unless the Edelbrock carb worked really nice, leave the Holley on it. As long as it is properly sealing, tune it to your motor and enjoy it.
Been having progressive louder engine noise, today I heard metal on metal. Like sounds of something flinging off into the oil pan. So I dropped it off at a buddies diesel truck shop for a lower rebuild.
Thoughts on parts to upgrade from stock with this rebuild? Bigger cam? Or shipping it somewhere to have it ported/stroked? Or just get a crate engine?
Thoughts on parts to upgrade from stock with this rebuild? Bigger cam? Or shipping it somewhere to have it ported/stroked? Or just get a crate engine?
Olds 307 and 403
Well-known member
At minimum you want a piston like the new Mahle 10cc forged pistons Cutlassefi brought to the market. He also has complete 4" billet stroker crank assemblies for around 420 ci. I am sure he could build your short block.
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