307 lovers and haters. I got a good one for you.

[78Delta88]

307 gets a lot of bad press, it's actually not a bad engine but was never really designed with performance in mind, plus very little support and especially when it comes to heads.

Your 307 swap should do what you want, but like others said 455 carb might be a bit much. Nice thing about Q-Jet is if the primaries are close in size between the two, you might be able to tune it and still come out ok.

If you are only going 30 miles I would just put the 650 on it.

If you do want to go TBI I have one for Chevy 305 and 454, and C3 systems for vin Y 307. Doing some of the restorations and saves over the years, just put stuff in boxes.

 

[Brodewok]

307 gets a lot of bad press, it's actually not a bad engine but very little support and especially when it comes to heads.

Your 307 swap should do what you want, but like others said 455 carb might be a bit much. Nice thing about Q-Jet is if the primaries are close in size between the two, you might be able to tune it and still come out ok.

If you are only going 30 miles I would just put the 650 on it.

I know you're right. I'll start with the 650. If it's acting up I'll trust the 800 to get me home tho.
I'm only going to try this because of my love for 307s. If I didn't have faith in em I'd just call AAA.
If it seems to have the speed limit and it surprises me with just needing tweeked I'll tune a 750 Rochester for it and leave it in the car. I have no shame. I live in the Seattle area tho so there's hills everywhere. But the vin y 307 tugs my equally heavy 82 ninety eight around no prob. So if my calculations are correct the vin 9 should be slightly better in the 68.
Only one way to find out.

 

[78Delta88]

Curious how it works out. I have an 83 98 with 307/2004R. Bought it like 8 months ago, still havnt driven ... It hit a deer. So it sits...

 

[Brodewok]

Curious how it works out. I have an 83 98 with 307/2004R. Bought it like 8 months ago, still havnt driven ... It hit a deer. So it sits...

Dammit! That's the one bad luck moment I haven't had happen yet.
How bad was it? Front clip/hood/fender? Did it make it to the radiator?

 

[78Delta88]

Driver fender and Header Panel.

Have the parts just need time to do it. Was one owner car white with white vinyl top. Of course Arizona sunlight killed the top. Other than that, it's in fairly good shape for its age.

But do wish it had a 350...

 

[Brodewok]

Driver fender and Header Panel.

Have the parts just need time to do it. Was one owner car white with white vinyl top. Of course Arizona sunlight killed the top. Other than that, it's in fairly good shape for its age.

My first 98 was a 82. I was 19 in AZ it was light beige on light beige on light beige. It was also toasted from the sun. Other than that mint condition. It was my favorite car ever. Lost it because I broke up with a girl and I left it at her house. Got it for 400$ in 1999. About ten years ago I decided to find a replacement. I had to fly to salt lake City and drive it back. The guy thought I was crazy. He was honest about it's condition and said he doesn't know of any major issues why it won't make it back to Seattle but he also said he would never do it. I laughed and handed him the 600$ and drove off into the sunset. Then I realized soon after that these parts aren't 10$ at the junkyard anymore. I paid 80$ for a small piece of rocker chrome and had to have it shipped from Georgia. Times have changed. But it's running good. it's been my daily ever since. Looking for a replacement 200 4r and a driver's fender. I'll kill for a brown leather interior.

 

[Wageslave]

If you are careful selecting your donor, it should be a pretty easy swap. The only real problem will be getting the computer controlled distributor that mounts to the 307 block. I don't remember if there are any factory drop in replacements or if you have to repin a CCC distributor to get timing control on TBI. The Oldsmobile gurus on here would know more than me on that.

As far as the computer and wiring harness, I would go for a 1988-1994 Chevrolet truck with a 305 for the wiring harness and the 1227747 computer. If you can't find a 305 vehicle to pull the harness from, you can grab a 350 setup and swap the injectors in the throttle body for 305 ones and buy a 305 PROM for the computer or just buy a whole 305 computer.

I just pulled the whole harness and every component that it attached to it out of the donor truck and strung them through my Pontiacs engine bay in roughly the same positions that they were laid out in the truck they came from. Everything mostly fit without modifications and only needed about 4 or 5 wires to interface with the car.

I did use a Ford fuel pump mounted on the frame instead of changing over to an in-tank setup, but factory TBI fuel pumps are available for G Body's so either is doable.

 

[Brodewok]

If you are careful selecting your donor, it should be a pretty easy swap. The only real problem will be getting the computer controlled distributor that mounts to the 307 block. I don't remember if there are any factory drop in replacements or if you have to repin a CCC distributor to get timing control on TBI. The Oldsmobile gurus on here would know more than me on that.

As far as the computer and wiring harness, I would go for a 1988-1994 Chevrolet truck with a 305 for the wiring harness and the 1227747 computer. If you can't find a 305 vehicle to pull the harness from, you can grab a 350 setup and swap the injectors in the throttle body for 305 ones and buy a 305 PROM for the computer or just buy a whole 305 computer.

I just pulled the whole harness and every component that it attached to it out of the donor truck and strung them through my Pontiacs engine bay in roughly the same positions that they were laid out in the truck they came from. Everything mostly fit without modifications and only needed about 4 or 5 wires to interface with the car.

I did use a Ford fuel pump mounted on the frame instead of changing over to an in-tank setup, but factory TBI fuel pumps are available for G Body's so either is doable.

All good info. see I forgot about the distributor situation entirely. Also didn't think about the inline pump. that would make things easier. How would VSS and cts tie in? Would the olds O2 sensor work or would I be using a different one from Chevy? Does it thread in to the olds hole? Is there a CPS?

Also I don't mean to waste anyone's time on this subject. The TBI conversation might only be wishful thinking. But this all does help me clearify the idea, making it more possible.

The only difference with the 350 and 305 TBI is the injectors and prom? Or is it computer too?

What kind of mileage would I expect with a vin Y 307 / 700r4 / 305 TBI / economy PROM / 82 olds 98 / can't remember the rear ratio but it's very highway.

 

[Wageslave]

The Olds O2 sensor would work, but I would recommend upgrading to a heated O2 sensor to get it into closed loop faster. VSS signal can be either be pulled from the cruise control circuit or an inline VSS can be added to the speedometer cable. I don't think there is a CPS signal, but there may be a pin that senses whether it is in park that controls fast idle. That can be tapped from the column switch though.

Yeah, the base throttle body is the same between 305 and 350 with different injectors depending on engine size. The computer is also the same with different PROM chips for different engine and transmission combos.

As far as mileage goes, I wouldn't expect crazy high mileage in this application. 98's aren't exactly light, and you likely have 2.29 or 2.43 gears in the back. It will be doing a good bit of work getting up to speed, although will likely purr right along once up to speed. TBI is an evolutionary step up from CCC, but it won't overcome physics. What it will get you is turn key starts in any weather and a much better ability to tell you what is wrong if something isn't right with the system. If you can find someone that still burns PROMS for TBI computers and can get the lean cruise enabled you might see a good jump in highway mileage, but those people are like finding ghosts anymore.

 

[olds307 and 403]

I ran a 94 TBI on an Olds 350 in a Z71 4x4. The colours are the exact same except the extra black wire is grounded. The connector is different at the distributor. Closed loop ran shitty, especially below -15C. Open loop ran really nice. The timing curve is super lazy on those sbc, below 10 TDC base timing it ran like garbage. The factory 20 the 307 had would work, I was running 19. The 307 was a very durable engine, I got 450,000 km before the timing chain skipped. I could have changed it and ran many more miles.