Hi all, new to the site I'll try not to be a pain in the, well you know.
I have a 76 hi boy with a 360 4 speed & 4:11 gears. My motor is getting tired, the heads are all pitted around the exhaust ports causing never ending exhaust leaks. So it's time for a new motor. I would like to replace the 360 with a 300 6. Do the bellhousings match up on these 2 motors? Or do I need to get a different bellhousing.

Cheers to all.

 

No match.

Find a six with a stick bell. Clutch linkage and z-bar will be different in addition to all the other stuff you'd expect.

 

Thanks, that is what I thought. What should I expect to pay for a 300 thats not trashed?

 

Find a beat up van, nobody wants those...you can get the whole thing for $500. Maybe.

Go through it first, at least bearings and a new rear seal. Valve seals would be a good idea too. These motors last a long time but not forever.

EFI exhaust manifolds, an Offenhauser 4 bbl manifold and small 4bbl will give you almost the same power a fresh stock 360 would push. Add a cam and you'll really be running.

 

Reddman, I've been considering swapping my 360 for a 300 also, have you made any progress?

 

Sorry I haven't, but it all seems pretty straight forward since we don't have to worry about all that computer crap.
Just haven't had the time & my tractor decided to drain my wallet, so some projects got put on hold.

 

I have done it and love the result. By building my engine I retained the same hp as the 360 (with a 2v carb), and gained 50% better mpg.

The thing about the 300 is nobody wants them, so the engines are very inexpensive on Craig's list. You want one with all the goodies, ps, alt, etc. It is best to use a pre efi head, even pre '84 if you can find one. Pre 84 heads are easier b/cause of the stud type rockers, instead of pedestal. But many use the pedestal type. I would avoid the smog type head.

The main differences are: You'll have to have a rad. shop change your inlet/outlet. That will run about $75. You'll also need to change your trans. The thing you need is to move your motor mount towers forward on the frame. The hole is already there. But take the actual motor mounts when you take the engine.

If I were you I would spend so $ on your head, having it ported, cleaning up the bowls too. That, with a nice 3 angle valve job, and a 30* back cut on the intakes, will bump you hp and just help the engine breathe. Get a cam kit according to what you want the engine to do, and that will take the performance up another notch.

This is the bottle neck of the 300. I opted for installing larger valves in my engine, and have never regretted it. Find a 4v intake, and install efi exhaust manifolds into free flowing exhaust (the need for back pressure is a untrue myth), and you'll get plenty of power. Then add a Duraspark 2 dizzy, recurved, and away you go.

There are many options available for more power. Check the I6 forum here, and read and copy/paste to a folder. There is a lot of information there.

The main difference between an inline 300 and a v8 is that the 300 is a tractor engine. It develops its peak torque at a lower rpm than v8's. There is also the 'bling' factor. Everyone has seen a million hp v8's, but with a hp inline you open your hood and people stop and remark.

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