how do i upgrade a 4.3L olds

[Hoopty_Mike]

would a grand national turbo work for my engine with a few modifications to it an could i get help on how

Simply put, no. That engine doesn't flow enough and would require a ton of machine work to do so, and handle any real amount of boost.

Look on your local craigslist/kijiji for a complete oldsmobile engine. You will be ahead at the least 50hp from what you have now if you picked up a 350/403. Which I bet you could find for under 500 bucks, which is less than a rebuilt GN turbo. I had a chance to pick up a low mileage 72' 7A headed olds 350 for 150 bucks, which was a conservative 160hp, and that was rated through a set of exhaust manifolds and a single exhaust. Might of even been the 2 barrel model, not sure. An engine like that would be much happier with a few bolt ons, and you would be way ahead of the game if you ever wanted to yank it out and build it for some serious power. Just my .02, I really think you should just leave the 4.3 the way it is for now.

 

[DoubleV]

81KiddCutty, you really need to just accept the fact that turboing a 260 or trying to get any real power out of it is simply not going to happen. Your just wasting time even considering it. It is by far the worst direction to go in if you're looking for performance. You have plenty of good alternative options. Choose one that fits your budget/mechanical apptitude and you'll thank yourself later. Again, the Olds 260 is COMPLETE GARBAGE as a performance motor.

 

[81KiddCutty]

would a grand national turbo work for my engine with a few modifications to it an could i get help on how

Simply put, no. That engine doesn't flow enough and would require a ton of machine work to do so, and handle any real amount of boost.

Look on your local craigslist/kijiji for a complete oldsmobile engine. You will be ahead at the least 50hp from what you have now if you picked up a 350/403. Which I bet you could find for under 500 bucks, which is less than a rebuilt GN turbo. I had a chance to pick up a low mileage 72' 7A headed olds 350 for 150 bucks, which was a conservative 160hp, and that was rated through a set of exhaust manifolds and a single exhaust. Might of even been the 2 barrel model, not sure. An engine like that would be much happier with a few bolt ons, and you would be way ahead of the game if you ever wanted to yank it out and build it for some serious power. Just my .02, I really think you should just leave the 4.3 the way it is for now.

i have an 85 grand national engine in my hands thats why i was asking and ahead of time no i will not put the gn in it im wanting to keep it olds all the way

 

[hurst1979olds]

Ive been seeing these threads on here about how to upgrade a 260 or a 307. All you guys are saying to blow it up, use it as a boat anchor, shoot it, etc..... I guess I was a little crazy for using an Olds 350 as my mailbox.....

 

[1bad79]

you cant thats the answer,the only thing thats immpressive about an olds 260 is how little power comes from such a gigantic engine [phyical size] :lol:

 

[442_olds]

81KiddCutty, you really need to just accept the fact that turboing a 260 or trying to get any real power out of it is simply not going to happen. Your just wasting time even considering it. It is by far the worst direction to go in if you're looking for performance. You have plenty of good alternative options. Choose one that fits your budget/mechanical apptitude and you'll thank yourself later. Again, the Olds 260 is COMPLETE GARBAGE as a performance motor.

I had a 260 in a '79 Supreme...absolutely the most underpowered Olds motor ever made. Don't waste your money trying to improve it...you can't. Save your money, and find a 350-403, or even a 455, which can actually be cheaper to build. All of them will bolt in with the same mounts, just make sure you get a good transmission. The TH200 will not hold behind even a 307 for very long. Keep an eye on Craigslist...you might be able to find a complete setup ready to go for a reasonable price. You will be money ahead going that route.