Replacing 78 231 3.8L with later 252 4.1L V6 questions

[Boydness]

Fuel line needs modified. Will the front inlet cause a fitment issue?

When I looked, I saw that it will be close, it sticks out just above the water neck.
Although, I figure that a spacer should be able to raise it above the water neck if it is too close.

 

[Clone TIE Pilot]

The 4.1s used a side inlet Qjet housing. The idle tubes for the 4.1s are tiny compared to more common V8 Qjets.

I kind of wish my Regal had a 231 in it. Good gas mileage and power.

No you don't. Stock n/a 231 only has 110 HP (pretty poor power even by 80s standards) with a very low 8.5:1 CR and very poor flowing heads. You could install a 4bbl carb and intake, headers, dual exhaust and it would make 120 HP. You have to take them apart and rebuild them to better specs, or install a intercooled turbo setup like GM did. This is why I swapped mine out for a HO 305, it makes double the power while still getting the same MPGs as the 231.

 

[ronbz455]

I would love to build an all out racing 4.1 and see how it performs but don't know the pros and cons of it. If you get a phenolic Qjet spacer than that carb should work with the clearance.

 

[olds307 and 403]

Get the 1" thick Mr Gasket 4 hole phenolic spacer, comes with gaskets, studs and nuts. You can also use a different filter and the short housing off the side inlet carb. Some Turbo Buick guys are running 4.1 blocks.

 

[Blake442]

Since it's got a Buick 3.8 in it right now, it'd be foolish to do anything other than put a Buick 350 in it.
The V6 to V8 swap is about as simple as it gets, and you'll never be happy with the V6 power unless you put a turbo on it...

 

[Boydness]

I would love to build an all out racing 4.1 and see how it performs but don't know the pros and cons of it. If you get a phenolic Qjet spacer than that carb should work with the clearance.

Get the 1" thick Mr Gasket 4 hole phenolic spacer, comes with gaskets, studs and nuts. You can also use a different filter and the short housing off the side inlet carb. Some Turbo Buick guys are running 4.1 blocks.

That was the exact spacer kit that I was considering using; although I am not sure I understand how to go about using a different filter and the short housing off of the side inlet (original) carb. Is there a link to a post or someone's setup? I did not think that I would be able to modify the front facing inlet any way.

Since it's got a Buick 3.8 in it right now, it'd be foolish to do anything other than put a Buick 350 in it.
The V6 to V8 swap is about as simple as it gets, and you'll never be happy with the V6 power unless you put a turbo on it...

I have been know to be foolish. I am considering the Buick 350 and even a SBC, although the top contender might be the '95 Firebird 3800 setup. My primary focus is to make the wagon drivable and then consider the options to improving the vehicle.