LS Swap into 1970 Buick Skylark

Loves302Chevy

"One test is worth a thousand expert opinions."
A friend of mine, Geoff, is going to swap an LS engine & transmission from a Cadillac Escalade into his 1970 Buick Skylark. The LS engine has 180,000 miles, and the rest of the vehicle is BEAT, to say the least. I hope the engine and transmission had better care. He says it runs great.
So I'm just asking for any info and tips any of you members might have on doing this swap, such as needed items, things that need to be converted, problems that might be encountered, etc. Thanks.
 
Thanks Grumpy. I'll check all the links out.

BTW, the Skylark has a 455 in it now.
 
I guess it is getting tired.
Plus he just wants to be able to take the car for long cruises, with all the modern comforts,
get a bump up in the HP department, and better gas mileage.
 
I had a 70 Buick Wildcat. 370 HP 510 torque stock. Could rebuild to those specs.

Swapping to LS is all the rage. It's a lot of work and costs a lot more than people think when you add up all the little things. Then after it's done it seems like there's constantly gremlins popping up especially when higher mileage ones are used. Have him price out an exhaust system, fuel system, and electrics involved as well as the possibility of the intake system being too tall for the Skylark before jumping on the band wagon. You never have problems with TPS, MAF, Oxygen, knock, CPS, and other sensors with old school engines.

The lure of "modern reliability" and better gas mileage seems to draw people in. While a "NEW" car is reliable (in theory) swapping an old engine, trans, and associated electronics is not likely to be reliable (stuff gets old and wears out). Simple old school engines are pretty reliable. Gas savings is a small incentive when you look at the numbers so lets look at the numbers on the high side.. Average hot rod gets less than 5,000 miles a year. So if he drove 5000 miles at $3.00 /gal and went from 10 MPG to 20 MPG he'd save $750.00 a year on gas. That's not much compared with the time and expense to get there and the real world numbers will probably be substantially less.

IF he goes through with the LS (did Escalade's come with the aluminum LS or just the iron block versions?) I'll bet the project takes 2 years from start to finish and costs 5-10 grand by the time he's done.
 
I had a 70 Buick Wildcat. 370 HP 510 torque stock. Could rebuild to those specs.

Swapping to LS is all the rage. It's a lot of work and costs a lot more than people think when you add up all the little things. Then after it's done it seems like there's constantly gremlins popping up especially when higher mileage ones are used. Have him price out an exhaust system, fuel system, and electrics involved as well as the possibility of the intake system being too tall for the Skylark before jumping on the band wagon. You never have problems with TPS, MAF, Oxygen, knock, CPS, and other sensors with old school engines.

The lure of "modern reliability" and better gas mileage seems to draw people in. While a "NEW" car is reliable (in theory) swapping an old engine, trans, and associated electronics is not likely to be reliable (stuff gets old and wears out). Simple old school engines are pretty reliable. Gas savings is a small incentive when you look at the numbers so lets look at the numbers on the high side.. Average hot rod gets less than 5,000 miles a year. So if he drove 5000 miles at $3.00 /gal and went from 10 MPG to 20 MPG he'd save $750.00 a year on gas. That's not much compared with the time and expense to get there and the real world numbers will probably be substantially less.

IF he goes through with the LS (did Escalade's come with the aluminum LS or just the iron block versions?) I'll bet the project takes 2 years from start to finish and costs 5-10 grand by the time he's done.
I completely agree with you, but he is tired of dealing with a carburetor.
Personally, I would not do the swap with a 180K mileage engine & trans which he got for $350.
He thinks he can do the entire conversion cheap - I don't think so.
 
You're right, won't be cheap. Need engine mounts, trans cross member, driveshaft mods, probably an (expensive) oil pan, modern electric pump fuel system, stand alone engine/trans harness or modify stock one, headers & exhaust mods, new shifter, and oxygen sensors. Probably also need different intake, possibly different serp belt set up, possible engine cross member mods (if AC depending on compressor mounting) radiator for LS and electric fans. Then there's a ton of little stuff that adds up quick. He certainly won't be the last to think it can be done cheaply or easily. Good luck to him if he attempts it.

If he thinks dealing with a carb is a hassle he's in for a big surprise.

Gear vendors overdrive runs about 3 grand.
 
You're right, won't be cheap. Need engine mounts, trans cross member, driveshaft mods, probably an (expensive) oil pan, modern electric pump fuel system, stand alone engine/trans harness or modify stock one, headers & exhaust mods, new shifter, and oxygen sensors. Probably also need different intake, possibly different serp belt set up, possible engine cross member mods (if AC depending on compressor mounting) radiator for LS and electric fans. Then there's a ton of little stuff that adds up quick. He certainly won't be the last to think it can be done cheaply or easily. Good luck to him if he attempts it.

If he thinks dealing with a carb is a hassle he's in for a big surprise.

Gear vendors overdrive runs about 3 grand.
I completely agree with everything you have said, but I just spoke with Geoff and he knows a bunch of friends
with all sorts of LS stuff just laying around. So he still thinks he can do this cheap. We will see.
I mentioned the overdrive idea (which I think is an excellent idea), but Geoff seems like he already has his mind
made up. He is also not planning to sell the 455 engine.
The Escalade block is cast iron. Geoff is debating whether to have the bottom end refreshed, and put a cam in it.

I'm with you guys on this. There is more to this this than he realizes.
 
Plus that 455 is a beast engine quite capable of some serious numbers with out replacing everything. My sbc 383 the only thing left stock on it is the block front and rear main cap.
 
Ive only built a few 455 buicks but they can be made to produce very respectable power,
I like them much more than 455 OLDS engines,
(personal prefference, lots of guys like olds)
they are at least the equally easy to work on as pontiac ,
FE ford, 385 FORD and mopar WEDGE,
and a bit easier than the 500 caddy,
and in my opinion easier than the current LS chevy.
given a choice ID go 392 hemi, 426 hemi or BBC almost every time
 
So Geoff is going ahead with the LS swap. My question(s) at the end of this is going to be about combining mostly factory and
aftermarket LS parts for a best bang-for-the-buck build. Parts he's collected so far:
LQ9 (Gen IV?) engine from a Cadillac Escalade with computer and harness
Heads - I think he already purchased them, or is looking at ....0823 (L92?) with the rectangular intake ports
LS3 factory intake
92 mm throttle body

He is looking to have the short block refreshed. He is getting camshaft recommendations all over the place, but has it narrowed
down to the GM LS Hot Cam 12480033
Jegs "Hot Cam" 555-200578
Jegs 249-54-426-11
Summit recommends Comp Cam 54-451-11

Remember, this is going into his 70 Buick Skylark that had a 455. He wants to be able to just jump in and cruise to New Hampshire
from Connecticut at will. So the combination needs to be built to cruise - think TQ not HP. He would actually like to use the exhaust
manifolds that came in the Escalade, unless too restrictive, with dual exhaust.

He knows he needs to get the Holley car oil pan.

Any HELP and questions/comments are appreciated. Mike.
 
So Geoff is going ahead with the LS swap. My question(s) at the end of this is going to be about combining mostly factory and
aftermarket LS parts for a best bang-for-the-buck build. Parts he's collected so far:
LQ9 (Gen IV?) engine from a Cadillac Escalade with computer and harness
Heads - I think he already purchased them, or is looking at ....0823 (L92?) with the rectangular intake ports
LS3 factory intake
92 mm throttle body

He is looking to have the short block refreshed. He is getting camshaft recommendations all over the place, but has it narrowed
down to the GM LS Hot Cam 12480033
Jegs "Hot Cam" 555-200578
Jegs 249-54-426-11
Summit recommends Comp Cam 54-451-11

Remember, this is going into his 70 Buick Skylark that had a 455. He wants to be able to just jump in and cruise to New Hampshire
from Connecticut at will. So the combination needs to be built to cruise - think TQ not HP. He would actually like to use the exhaust
manifolds that came in the Escalade, unless too restrictive, with dual exhaust.

He knows he needs to get the Holley car oil pan.

Any HELP and questions/comments are appreciated. Mike.
They all use really wide lobe centerline cams Mike LS Engines.
Unlike what we are used to in the Old School musclecar world.
Makes for easy EFI Tuning & no intake pulse reversions to skew the MAP sensor readings.

I LS swapped a LS3 into a 1970 Chevelle last Year at the race shop.
It was a shame to pull out the 454 engine.
Built to LS5 specs.

What you have to watch out for is Hood clearance with an OEM steel hood.
LS intakes are all tall.

Despite using the best availoable adjustable motor mounts the aftermarket Holley Stealth Ram hit the hood,
Original Functional Cowl Induction.
I refused to do it...
They bent the inner lip that interfered with Pliers.
$5,000 Hood today.
Throttle body had to be flipped upside down too.

No LS swap seems to be the same.
 
If He is not Racing I would not pay much attention to Cams.
Honest.
Due to the nature of LS Cathedral port or Retangular port heads,
Power will not come on hard till 4,000 Rpms.
Large cross sectional port area prent in the intake ports.
Velocity is there but not like many musclecars.

If you install a cam be sure to clay check PTVOC.
Many LS engines have flat tops no valve reliefs.
I got into an argument with the Ex boss on the LS3 engine I hand built from a bare block.
He said Checking PTVOC was a waste of time.
I won & got my way.
Just enough with a High lift cam & flat tops with valve reliefs.
 
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