350 rocket mild modifications
#1
350 rocket mild modifications
Wanted to ask a restoration question and then a modification question. I have an automatic and when my car tries to change gears when accelerating it screeches and then slams the gear sometimes even very late just wondering what that could be if anyone could help me out on that??? Also, after I get that fixed I want to start making upgrades as far as performance and thought I'd start with a Holley 4 bbl vacuum secondary single inlet carb, a new summit racing header-back dual exhaust system, and new headers, but not sure which ones I should get. Hedmen Hedders seem to have quality headers for a fair price but any advice would be greatly appreciated and this car would only be for street use I just wanted to add some more horsepower to my Oldsmobile and get it running better
#2
The first question is, what trans do you have in your 68 - TH400 or Jetaway?
As for the mods, no one makes headers that will fit the 1965-70 Delta 88s. They have a unique rear steer configuration and there isn't room for headers. You won't really be able to run dual exhaust on your 350. These cars require a unique exhaust manifold on the driver's side to clear the steering box and starter. Unfortunately, the 1965-70 D88 was never offered with dual exhaust on the small block. so that manifold (which is available as a repro) was only offered for the big block. I recently installed one on my 67 D88, and the configuration MAY fit an SBO, but no guarantees.
A properly rebuilt Qjet will perform better than any Holley, especially on a heavy car like a D88 with a small block. I wouldn't waste my time or money on a different carb. Start by getting your stock configuration properly tuned up and fix any maintenance issues and THEN worry about mods.
As for the mods, no one makes headers that will fit the 1965-70 Delta 88s. They have a unique rear steer configuration and there isn't room for headers. You won't really be able to run dual exhaust on your 350. These cars require a unique exhaust manifold on the driver's side to clear the steering box and starter. Unfortunately, the 1965-70 D88 was never offered with dual exhaust on the small block. so that manifold (which is available as a repro) was only offered for the big block. I recently installed one on my 67 D88, and the configuration MAY fit an SBO, but no guarantees.
A properly rebuilt Qjet will perform better than any Holley, especially on a heavy car like a D88 with a small block. I wouldn't waste my time or money on a different carb. Start by getting your stock configuration properly tuned up and fix any maintenance issues and THEN worry about mods.
#3
thanks for the response, I know it has a newly rebuilt trans but I don't know exactly what it is, also currently it does have a dual exhaust system set up and I have had problems with it there was an exhaust leak and I got that fixed but it still makes a clicking noise after driving it for a while, and I did find out that the exhaust had been rubbing on the drive shaft so I'll just go with the single exhaust and have the carb rebuilt, thank you very much!
#4
currently it does have a dual exhaust system set up and I have had problems with it there was an exhaust leak and I got that fixed but it still makes a clicking noise after driving it for a while, and I did find out that the exhaust had been rubbing on the drive shaft so I'll just go with the single exhaust and have the carb rebuilt, thank you very much!
#5
I'm curious as to how the driver's side pipe was routed. My 67 had a custom bent dual exhaust system when I got it, using the single exhaust manifold on the driver's side. The pipe was flattened to almost nothing to get it past the starter and steering linkage. That's why I swapped to the correct exhaust manifold and new pipes.
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What do you want to check it for? None of the Carfax-type sites will take a VIN this old that only has 13 digits. If you just want to decode it, post it here. There is very little info in the VIN - it's all what you can see by looking at the car. All it will tell you is that it's an Oldsmobile, the specific model and body style, the year, and the assembly plant.
#11
What do you want to check it for? None of the Carfax-type sites will take a VIN this old that only has 13 digits. If you just want to decode it, post it here. There is very little info in the VIN - it's all what you can see by looking at the car. All it will tell you is that it's an Oldsmobile, the specific model and body style, the year, and the assembly plant.
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Yeah it does and I thought the engine was a 350 because when I took the car to a mechanic recently I had told him it was a 455 but when he inspected the car he told me it was a 350, but I just called my uncle who's the person that sold the car to me and he said it's the original 455 so that must be why it fits like that
#15
[QUOTE=turley68delta88;970236]Yeah it does and I thought the engine was a 350 because when I took the car to a mechanic recently I had told him it was a 455 but when he inspected the car he told me it was a 350, but I just called my uncle who's the person that sold the car to me and he said it's the original 455 so that must be why it fits like that[/
I don't know why that mechanic said it was a 350 but my uncle said its the original 455 with the original miles and I did find out it has the original 350 turbo automostic transmission I'm honestly not familiar at all really with transmissions but he said he had recently had it rebuilt before he sold it to me
I don't know why that mechanic said it was a 350 but my uncle said its the original 455 with the original miles and I did find out it has the original 350 turbo automostic transmission I'm honestly not familiar at all really with transmissions but he said he had recently had it rebuilt before he sold it to me
#16
I don't know why that mechanic said it was a 350 but my uncle said its the original 455 with the original miles and I did find out it has the original 350 turbo automatic transmission I'm honestly not familiar at all really with transmissions but he said he had recently had it rebuilt before he sold it to me
#18
My uncle owned the car before me and he said and so I asked him what the transmission was and he said it was the 350, but wasn't sure so it probably is just the TH400
#19
#23
That is the block casting number for all 455s from 1968 through 1976.
To know exactly which 455 it is would have to be determined from the application, which in your case (if I remember your posts correctly) is a 1968 Delta 88 455-4bbl dual exhaust.
I don't have ready access to the 1968 engine specs but they are likely the same as 1969 which was 10.25:1 compression ratio, 365 hp @ 4600 RPM and 510 lb-ft @ 3000 RPM.
To know exactly which 455 it is would have to be determined from the application, which in your case (if I remember your posts correctly) is a 1968 Delta 88 455-4bbl dual exhaust.
I don't have ready access to the 1968 engine specs but they are likely the same as 1969 which was 10.25:1 compression ratio, 365 hp @ 4600 RPM and 510 lb-ft @ 3000 RPM.
Last edited by Fun71; November 24th, 2016 at 01:31 PM.
#25
That is the block casting number for all 455s from 1968 through 1976.
To know exactly which 455 it is would have to be determined from the application, which in your case (if I remember your posts correctly) is a 1968 Delta 88 455-4bbl dual exhaust.
I don't have ready access to the 1968 engine specs but they are likely the same as 1969 which was 10.25:1 compression ratio, 365 hp @ 4600 RPM and 510 lb-ft @ 3000 RPM.
To know exactly which 455 it is would have to be determined from the application, which in your case (if I remember your posts correctly) is a 1968 Delta 88 455-4bbl dual exhaust.
I don't have ready access to the 1968 engine specs but they are likely the same as 1969 which was 10.25:1 compression ratio, 365 hp @ 4600 RPM and 510 lb-ft @ 3000 RPM.
#27
Yeah I know I think that's what I might have, in my earlier post I just said I was thinking of putting a 4 bbl carb in there if I could but I'm just going to rebuild the carb and worry about regular maintenance for now
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