12 bolt swap from 10 bolt

[1969chevmalibu1969]

Working on getting things lined up for the rear install I am finding some changes from the 10 bolt. I thought that the u bolt would work, but when I tried it it was to small. After some research it needs to have the bolt and strap set as the holes are threaded. Called a place ( can’t remember name off hand) she was very helpful. I sent some pictures because there are two types. She said she knew the exact ones. In going to call and order tomorrow and post place and product later. May add to project detail tread and put difference between my 12and10. So now to the question, will I now have to change my driveshaft to? Also going from th350 to th400.

 

[1969chevmalibu1969]

Added

 

[cheveslakr]

the th400 is longer, so you'll have to find another one or just have yours shortened. If yours is pitted, maybe now's a great time to get a new shiny one?? Your upper driver's side trailing arm from your 10 bolt won't work for the 12 bolt without mods. You can shave it down to fit the added mass of the pumpkin to work, but you'll have to add another layer of metal to strengthen it. I'll get a pic of one for you or just google the 12 bolt version and you'll see what I mean.

 

[cheveslakr]

Heres a fairly good pic of the added wafer the factory spot welded in. The lower rear corner of that same arm has been radiused to clear the pumpkin when it articulates, and the wafer insures the bolt won't worm out of a weakened area.

 

[1969chevmalibu1969]

So these would have to be modified? Or at least one?

 

[1969chevmalibu1969]

Lever-family-racing show a good picture

 

[1969chevmalibu1969]

View attachment 5454

Heres a fairly good pic of the added wafer the factory spot welded in. The lower rear corner of that same arm has been radiused to clear the pumpkin when it articulates, and the wafer insures the bolt won't worm out of a weakened area.

Is that wafer just a piece of metal welded? Thanks for all the heads up. I learned a lot last night researching.

 

[cheveslakr]

Yep, just 14 ga metal iirc....I have a couple arms here but they're fairly pitted. Would have to dig for personal pics.

 

[1969chevmalibu1969]

Did all the lowers have to be modified for a 12 or was there one for it originally?

 

[Molly's 70]

I think all the SS models came with beefed up lower trailing arms.

 

[cheveslakr]

The lowers were the same on all models unless the F41 rear sway bar was ordered, then the lowers received the support insert that prevented the through bolts from crushing the channel. This was just a welded insert, not a different lower bar. Year to year, there were slight changes in the bar stampings, but they will all interchange. The differences were a slight offset, vs. asymmetrical.

 

[1969chevmalibu1969]

The lowers were the same on all models unless the F41 rear sway bar was ordered, then the lowers received the support insert that prevented the through bolts from crushing the channel. This was just a welded insert, not a different lower bar. Year to year, there were slight changes in the bar stampings, but they will all interchange. The differences were a slight offset, vs. asymmetrical.

Is there a way to tell if mine had a rear sway bar originally? The rear I took out was a 10 bolt , but I’m almost positive it’s not the original. It does come up as a 69 Chevelle 10 bolt and has I think all the original rear suspension parts down to the nuts and bolts except I would have to see if the ones to the rear axles were. It’s kinda like a ss body on a Malibu frame. Also I haven’t checked what or where the th350 is and it’s tucked away. My driveshaft also measured 53.5 I think and I’ve been reading people with tg350 were measuring 55.5 then having to shorten an few inches for the th400 making mine about the length. Also my crossmember didn’t have original bolts leading me to think it was moved.

 

[Derek69SS]

69 was the first year of F41 option, and was quite rare with only 722 cars being so equipped, and only available on SS396 cars per GM documentation. I recall someone on TC claiming to have an original L48/4spd Malibu that was equipped with it, though I don't recall seeing any proof.
F41 included bigger front sway bar, a rear sway bar, reinforced lower arms, stiffer springs, and HD shocks.

Rear sway bar was ONLY available with F41 option.

In '70, F41 became standard on all SS models. (except El Camino)

 

[1969chevmalibu1969]

69 was the first year of F41 option, and was quite rare with only 722 cars being so equipped, and only available on SS396 cars per GM documentation. I recall someone on TC claiming to have an original L48/4spd Malibu that was equipped with it, though I don't recall seeing any proof.
F41 included bigger front sway bar, a rear sway bar, reinforced lower arms, stiffer springs, and HD shocks.

Rear sway bar was ONLY available with F41 option.

In '70, F41 became standard on all SS models. (except El Camino)

The rear came from a 69 Malibu with a 350. Not sure if it had the F41 or not.

 

[Derek69SS]

The rear came from a 69 Malibu with a 350. Not sure if it had the F41 or not.

1969 Chevelle Options

Decoding Chevrolet VIN, trim tags, cowl tags, engine, engine block casting numbers, cylinder head casting numbers, intake manifold casting numbers, transmission, interior codes, and paint codes.

www.chevellestuff.net

This page shows original option list, and shows F41 being only available on SS396.

 

[cheveslakr]

 

[1969chevmalibu1969]

View attachment 5465View attachment 5466View attachment 5467View attachment 5468

Thanks for the pictures. Wil a 70 be the same as a 69?

 

[cheveslakr]

Yep, but it's pretty easy just to modify yours.

 

[1969chevmalibu1969]

Yep, but it's pretty easy just to modify yours.

Is there a place for specifics or is it just a wing it with cutting bendy a welding on the reinforcement piece. When I put mine on the rear it looked like not much has to be cut and bent.

 

[1969chevmalibu1969]

With the topic of the rear frame brace going on with the F41. Is this the brace?