Big block into small block chassis differences?

[Takoctopus]

So I have a rusted out big block car and a solid small block car I want to drop the big block parts in. So far the only thing I really notice is the passenger side engine bay sheet metal is different. Does anyone know if there is anything else I need to remove sheet metal wise to install in the small block car besides the passenger engine bay wheel well? Both 74 RR, Thanks for any ideas

 

[WileE]

What models, may I ask, are you referring to ?

 

[Takoctopus]

What models, may I ask, are you referring to ?

Both 74 roadrunners, updated my post, forgot to add it earlier

 

[WileE]

Are you referring to the radiator support opening ?

 

[Takoctopus]

Are you referring to the radiator support opening ?

The passenger side on the engine bay has a huge hole to clear a big block where as the small block has a much smaller hole and cover. Primer car is the small block, blue is the big block car.
The radiator support looks to be the same size, wondering if there is anything else

 

[73HEMI_RR_GTX]

So I have a rusted out big block car and a solid small block car I want to drop the big block parts in. So far the only thing I really notice is the passenger side engine bay sheet metal is different. Does anyone know if there is anything else I need to remove sheet metal wise to install in the small block car besides the passenger engine bay wheel well? Both 74 RR, Thanks for any ideas

The K members are different
Small Block K member can be used with schumacher motor mounts. I personally would use the Big Block K member with stock mounts.

 

[MCODECUDA]

The passenger side on the engine bay has a huge hole to clear a big block where as the small block has a much smaller hole and cover. Primer car is the small block, blue is the big block car.
The radiator support looks to be the same size, wondering if there is anything else

View attachment 1298125

View attachment 1298126

Someone hacked a hole in the inner fender of the blue car. There are no differences between the inner fenders of a big and small block car.

 

[73HEMI_RR_GTX]

Someone hacked a hole in the inner fender of the blue car. There are no differences between the inner fenders of a big and small block car.

73 and 74 Big Block B Bodies had a large access hole in the passenger side inner fender from the factory and used a rubber splash shield to cover it.

Here's a picture of my 73 RR GTX as you can see the passenger side access hole from the wheel well looking towards the engine.

 

[Master Gunner]

Yup, and if you ever see a 440 in a original small block car, you'll know why they did that.

Mark

 

[Takoctopus]

The K members are different
Small Block K member can be used with schumacher motor mounts. I personally would use the Big Block K member with stock mounts.

View attachment 1306409

Thanks for the info on the K member, mine is rusted out on the rear mounts so this will come in handy when I shop for one

 

[73HEMI_RR_GTX]

Thanks for the info on the K member, mine is rusted out on the rear mounts so this will come in handy when I shop for one

Well,
you have Two K members to make one. Just a suggestion, you could remove the mounts from the rusted Big Block K member and replace on the Small Block K member.

 

[Nacho-RT74]

Someone hacked a hole in the inner fender of the blue car. There are no differences between the inner fenders of a big and small block car.

Incorrect... for those who are not familiar of course would think that, but 73/74 got that cut shown on Big Block cars... covered with a rubber matt attached with snap in clips

Fits 73 74 Charger Inner Fender Splash Shield 1973 1974 | eBay

 

[Takoctopus]

Well,
you have Two K members to make one. Just a suggestion, you could remove the mounts from the rusted Big Block K member and replace on the Small Block K member.

Just have one K member. Other car is basically striped but solid.

 

[73HEMI_RR_GTX]

What do the stripes look like?

Don’t you have anything better to do than Trolling the forum looking for reasons to put down others? Or does acting like an *** feed your ego?

 

[YY1]

Torsion bars are also different.

 

[Nacho-RT74]

Torsion bars are also different.

And sway bar, but that's not excessively critical. No mod needed but a replacement. The only problem on this is the lack of options from shops if wishing new parts.

 

[YY1]

They made a LOT of 400 powered Cordobas.

.....but did anyone save the parts?

 

[Takoctopus]

Everything is coming out of the big block car and going to the small block car, already have the passenger side wheel well pulled to weld into the small block car. The knowledge here is pretty good. It’s helps to have people to bounce ideas off of.

 

[MCODECUDA]

Everything is coming out of the big block car and going to the small block car, already have the passenger side wheel well pulled to weld into the small block car. The knowledge here is pretty good. It’s helps to have people to bounce ideas off of.

Why not just make a pattern and cut up the small block inners or just not cut or replace them at all?

 

[Takoctopus]

Why not just make a pattern and cut up the small block inners or just not cut or replace them at all?

Just have to change over the one side, I have seen people put big block in small block cars but it get tight. I could just cut up the small block car but it’s cleaner to remove the spot welds and weld it back in.