1966 valiant worth getting a 230 (or 240 can’t remember the numbers)

[moparkrazed]

Hey guys. I have a 66 valiant with a 170 and an a 903 in it now. My aunt has a 1966 225 slant six that I’ll probably upgrade to (currently have a 170 in there that I’ll keep and rebuild eventually because it’s original to the car). If I get a 225 and do some upgrades like a small cam and bore it .20, would it be worth upgrading to an a 230 or a 240 whichever it is. Or are the basically the same with the exception of a synco 1st gear? Thanks in advance for everyone’s feedback.

 

[65 Cuda 340]

If memory serves, the 230 was strong enough to run behind a 340. I put one in my old 65 Valiant after swapping the 170 for a mildly hopped up 225. It worked well. You do have to cut the floor and run a hump for clearance for the floor shifter.

Then I found an early cast iron slant six four speed bellhousing, and used it to swap in a four speed (with 3.09 low gear). That was one of the most fun driving cars I've ever owned.

 

[RustyRatRod]

A230s came behind big blocks as well. Your problem is going to be that it will not fit in the stock transmission tunnel. You're going to have to do some creative stretching. I plan on using a port a power on mine. It will also hit the top of the tunnel just above where the cross member is. It's not by much though and I think a creative dent would make it happen. I've tried it in my 64. It doesn't fit. So I put my A903 back in it "for now".

 

[moparkrazed]

If memory serves, the 230 was strong enough to run behind a 340. I put one in my old 65 Valiant after swapping the 170 for a mildly hopped up 225. It worked well. You do have to cut the floor and run a hump for clearance for the floor shifter.

Then I found an early cast iron slant six four speed bellhousing, and used it to swap in a four speed (with 3.09 low gear). That was one of the most fun driving cars I've ever owned.

I thought I had read some were behind v8s as well. I also found that I can keep the column shifters by making the shift levers longer. Definitely still thinking through it and doing a ton of body work still. But I like to have ballpark plan and start heading in a general direction haha. Thanks for the reply 65 cuda.

 

[moparkrazed]

A230s came behind big blocks as well. Your problem is going to be that it will not fit in the stock transmission tunnel. You're going to have to do some creative stretching. I plan on using a port a power on mine. It will also hit the top of the tunnel just above where the cross member is. It's not by much though and I think a creative dent would make it happen. I've tried it in my 64. It doesn't fit. So I put my A903 back in it "for now".

Welllllllll that sucks lol. At least some creative stretching isn’t all that bad. I have body work and customizing experience so I can do some if that, but depends on how much needs to be done. Might just keep the 903. I finally got the 170 running and yard drove it ( still no brakes and got a little exciting when the porch was getting faster than I expected, but got it stopped haha). Thanks for letting me know about the fitment issues.

 

[moparkrazed]

A230s came behind big blocks as well. Your problem is going to be that it will not fit in the stock transmission tunnel. You're going to have to do some creative stretching. I plan on using a port a power on mine. It will also hit the top of the tunnel just above where the cross member is. It's not by much though and I think a creative dent would make it happen. I've tried it in my 64. It doesn't fit. So I put my A903 back in it "for now".

Do you think the a 903 will hold up behind the 225 with a slight bore and cam? Prob nothing too crazy.

 

[RustyRatRod]

Do you think the a 903 will hold up behind the 225 with a slight bore and cam? Prob nothing too crazy.

Sounds like mine is a lot stouter than what you're planning and I have the original A903. I don't know how much driving "like this" it will take. So far it's held up good, but this is the first I've gotten in it this hard.

 

[moparkrazed]

Sounds like mine is a lot stouter than what you're planning and I have the original A903. I don't know how much driving "like this" it will take. So far it's held up good, but this is the first I've gotten in it this hard.

Haha man that’s awesome. Love the sound and chop. Maybe I can go further than I planned with the motor.

 

[RustyRatRod]

Haha man that’s awesome. Love the sound and chop. Maybe I can go further than I planned with the motor.

I don't know. The A903 and 7 1/4 are both light duty units.....although plenty of people have run heck out of both without failure.

 

[moparkrazed]

I don't know. The A903 and 7 1/4 are both light duty units.....although plenty of people have run heck out of both without failure.

True. I have a 7 1/4 in my dart swinger and it’s holding up well so far behind a 318. But heck if it breaks just go bigger next time haha. Sounds great though and definitely appreciate all of the feedback. Definitely learned a ton from your posts with the early A stuff.

 

[RustyRatRod]

True. I have a 7 1/4 in my dart swinger and it’s holding up well so far behind a 318. But heck if it breaks just go bigger next time haha. Sounds great though and definitely appreciate all of the feedback. Definitely learned a ton from your posts with the early A stuff.

Well your car is a bit heavier than mine, but still light. The back end of yours is where some of that weight difference is. Mine is light as a feather in the rear, so that's a plus. I think though with bigger tires and trying to make it hook with the 2.93 open rear end, I'd find myself with a pile of scrap metal. The sure grip 7 1/4 is substantially stronger.

 

[moparkrazed]

Well your car is a bit heavier than mine, but still light. The back end of yours is where some of that weight difference is. Mine is light as a feather in the rear, so that's a plus. I think though with bigger tires and trying to make it hook with the 2.93 open rear end, I'd find myself with a pile of scrap metal. The sure grip 7 1/4 is substantially stronger.

That’s cool. Mine definitely isn’t a suregrip. I got a 1/2 of a parts car (my uncle cut the front clip off when he was alive and gave it to someone in GA) I was able to get the back glass, both rear quarters, roof, and trunk, Dutchman etc. it has a 7 1/4 are well but not sure it ls worth hanging onto. Need to cut a few more parts off then it will be gone and my shed full of parts. Can’t wait to have it finished and driving but still a lot of work to do.

 

[halfafish]

I have a 903 behind the stock slant in the same car as yours. That non-synchro first gear is the only can't-stand-it thing about the car. I will swap in a 230 and beat the tunnel if needed, or if my four-on-the-tree idea pans out, it will get an 833 OD with the same tunnel beating.

 

[RustyRatRod]

I have a 903 behind the stock slant in the same car as yours. That non-synchro first gear is the only can't-stand-it thing about the car. I will swap in a 230 and beat the tunnel if needed, or if my four-on-the-tree idea pans out, it will get an 833 OD with the same tunnel beating.

I don't think it's even enough to warrant "beatin on" as it does actually fit, width wise. There's just not enough room to attach the shift rods to the levers. That would be easily over come with a port a power.

The biggest issue I think it where it hits the center of the top of the tunnel above the cross member. the cross member lacked like 1/2" or so from lining the bolts up. I "guess" you could mod it so the mount sits lower in the cross member, but then you're messin with the drive line angles. I should have taken pictures and detailed it more. I'm sorry I didn't. I just wanted my little junk back on the road.

I might be gettin ready to put it down again and if I do, I'll detail it more in depth then. We'll see.

 

[RustyRatRod]

....also keep in mind, mine is a 64. Yours is a 66. I know the 4 speed humps are different for those years, so the transmission tunnel could be different and wide enough. You're just gonna have to "see".

 

[moparkrazed]

I have a 903 behind the stock slant in the same car as yours. That non-synchro first gear is the only can't-stand-it thing about the car. I will swap in a 230 and beat the tunnel if needed, or if my four-on-the-tree idea pans out, it will get an 833 OD with the same tunnel beating.

I think I ran across your post last night. I’ll have to keep an eye out to see if that works. Sounds like there is a way to get a shift lever under the dash for 4th. But that would be sweet if it works out.

 

[moparkrazed]

....also keep in mind, mine is a 64. Yours is a 66. I know the 4 speed humps are different for those years, so the transmission tunnel could be different and wide enough. You're just gonna have to "see".

Yeah I know 4 speed humps are hard to come by and different for 66. Would be interesting if the tunnel floor was slightly different. I wouldn’t count on it but never know with some of these Mopar’s haha.

 

[65 Cuda 340]

I just used a Duster hump in my 65 Valiant. Different than the OEM 65 hump, but close enough to be usable. I had no problem with either the 230 or 4 speed trannies hitting the crossmember or the bolts lining up. Never occurred to me to try to make a column shifter work with either trans. Guess I'm not as creative as some.

 

[moparkrazed]

I just used a Duster hump in my 65 Valiant. Different than the OEM 65 hump, but close enough to be usable. I had no problem with either the 230 or 4 speed trannies hitting the crossmember or the bolts lining up. Never occurred to me to try to make a column shifter work with either trans. Guess I'm not as creative as some.

Haha only reason I thought about it was reading a ton of posts on here…. And trying to be lazy and not do too much lol. The body work alone is driving me nuts, but it was the car my uncle wanted done before he passed and his family gave it to me to finish… so I gotta finish it lol.

 

[cudamark]

Get a 745 transmission that came behind the 273 (and some 6cyl's) that year. That should be a bolt in and your column and linkage might work with minor mods. Even the yoke is the same and maybe driveshaft length. It's a stronger trans than the 903, but not quite as beefy as the 230 or 833, which will need more mods to fit. Forget the 250, it's not much stronger than the 903 and I think has a different front bearing retainer.....or maybe it was the bolt pattern on the bell housing.....I forget. Isn't worth the swap anyway.

 

[cudamark]

Yeah I know 4 speed humps are hard to come by and different for 66. Would be interesting if the tunnel floor was slightly different. I wouldn’t count on it but never know with some of these Mopar’s haha.

For a 4 speed conversion, I think you'd just need the 4 speed hump or custom cutout for whatever floor shifter you decide to use. The transmission crossmember is the same and so is the pan reinforcement. They did have an 833 as a option you know, both for the 273 and slant 6! Mother Mopar didn't completely reinvent the wheel when they made that an option.

 

[moparkrazed]

For a 4 speed conversion, I think you'd just need the 4 speed hump or custom cutout for whatever floor shifter you decide to use. The transmission crossmember is the same and so is the pan reinforcement. They did have an 833 as a option you know, both for the 273 and slant 6! Mother Mopar didn't completely reinvent the wheel when they made that an option.

Thanks for the two posts mark. I’ll definitely have to research the other transmission, I don’t know much about those at all. Definitely appreciate the info man.