Hi everyone, I am very new to all this so bare with me. I am 16 and recently purchased a 1965 Jetstar 88 with as I was told a 425 in it. It had an aftermarket aluminum radiator to go with it. The motor ran for a few months and all the car needed interior restoration and a paint job along with many other cosmetic things. The motor has a hole in it now and I plan on putting a 455 in it. I have a 1975 455 out of a olds 98 and a parts motor from a 69 olds with class "c" heads. I was just wondering what some good ideas would be to do to make it fit and all the things I should redo on the motor? the 75 runs but needs new gaskets for sure. I want to use the original transmission.

 

Also any advice on what I need to make the 455 fit?

 

the 455 is a bolt in fit but is a low compression smog motor with around 190 to 230 hp not nearly what you had with the original 425. What you need to do first is figure out how much you want / have to spend on you engine. If not much just install the 455 the way it is and have fun with it and save your money for a quality rebuild using higher compression pistons and the C heads out of the 69 motor. the heads will most likely have to be rebuilt as well. We are talking 2k to 5k for a low buck rebuild and can go much higher for a hi performance engine. Of course the costs also depend on how much you can do yourself. Many other will chime in with advice as well

Good luck

 

The 65 Jetstar 88 came with a small block 330 only and some running gear from the smaller Cutlass. Now if your car is a Jetstar I then it was an original equipped 425 big block car. The 455 and 425 are the same size externally so there will be no fitting issues and will be a direct swap.

 

Watch your tongue there, young man! I take my clothes off for no one!

A hole in it? Socks get holes in the them. How does a motor get a hole in it? Where is the hole? How did it get there?

 

Well see that's what I thought to about being a 330 but I did my research and checked VIN codes and everything and the motor was indeed a 425. I have an original manual for the car that says the 425 was an option but I'm not certain its the original to the car. I was just planning on rebuilding the gaskets and maybe putting new valve train and cam on for now with the C heads but leave all the block and pistons the same. Is this a good idea or should I just replace gaskets on the 75 and leave it all stock? I wasn't planning on spending but maybe 1k for now, then down the road finishing the job off.

 

That depends on if you want more power and if you are going to want to pull the engine back out again. Too bad because the 425s are bad ***. Do the C heads look like runners? If so then its worth bolting those on. Also check the timing set in the running 455 to make sure its not the nylon gears. Change it out with a new set. Thats only like 60 bucks extra if your changing all the gaskets anyway. You should also shim the oil pump too for extra oil pressure. And use the intake from the 69 455 so you dont have that crummy egr intake. But all in all depends on what you like to do. I like the 60s stuff. Not emissions.

 

There are a few errors here that need correcting.

First Oldsmobile VIN's in 1965 did not indicate exactly what engine was in the car. They indicated only whether or not the engine was an L-6 or a V-8. So the VIN cannot tell you if the engine is a 330 or a 425 as both are V-8s.

Second, the only engine available in the '65 Jetstar 88 was the 330. The 425 was not an available option. The whole point was that if you wanted a larger engine, Olds wanted you to step up and pay a little more money for a Dynamic 88 or a Delta 88. If your car's engine really is a 425 and it's original to the car, then your car cannot be a Jetstar 88. If you're convinced the engine is original, are you sure the car is not a Jetstar I as Oldsmaniac mentioned? The Jetstar I was a sportier version of the Jetstar 88 made for only two model years, 1964 and 1965, and it came with the larger V-8 engine available in those years (394 in '64, 425 in '65).

The third digit of the car's VIN will tell you what it is. If the third digit is a 2, the car is a Jetstar 88. If the third digit is a 4, the car is a Jetstar I.

While the Jetstar 88 was offered in four body styles (two and four-door hardtop, four-door sedan, and convertible), the Jetstar I was offered only as a two-door coupe, called a Sports Coupe.

 

The C heads need completely rebuilt they are not in good condition. I would rather deal with the non emmisions stuff off the 69. The motor is already pulled out and I plan on pulling the motor out in the future to due a complete overhaul and put flat top pistons or whatever for more power but right now I am looking at something in good running shape that has a decent amount of power. Should I stick with the 69 intake like you said if it is a 2bbl, or should I go with the egr intake thats a 4bbl out of the 75?

 

Sorry I typed that wrong I mean the coding on the engine block to tell exactly what motor it was for sure. The motor is gone now but before I tossed it I checked and it was in fact a 425 according to the casting number and it had an enlarged intake, along with the same paint coloring as a 425. The motor must have been installed at some point in time because the car is a 1965 Jetstar 88 Holiday Coupe model. But, to double check if thats accurate I will copy the VIN when I get back home. Also, since you seem to know a lot about this model of car, what transmission came stock with the car and how will I be able to tell?

 

The only automatic transmission that could be gotten on the '65 Jetstar 88 was the 2-speed Jetaway. You can tell if this is the transmission on the car as the gear selector would show PRNDL.

If the car has a TurboHydramatic, it would have PRNDSL, where the S stood for "Super" in Oldsmobile parlance and second for anyone else.

 

As to which intake is up to you. Since your going to redo the engine in the future id chose whichever better running carb you have to determine your intake since you just want to drive and enjoy it. Later youll make it how you want. Just drive it and enjoy it. Once you are who cares what intake!

 

Welcome to CO! Glad to hear that someone your age loves Oldsmobiles. Bet that will stick out in the school parking lot. My 7 year old loves my Cutlass, hope he's still as interested when he's your age. Hope you're able to get your engine situation straightened out soon so you can enjoy your new ride.