Swapping an Engine


I just bought an '81 Buick Regal with an anemic V-6 engine in it. I understand a 350 Olds engine is a perfect swap. Is there anything else that needs to swapped out to make this motor fit right ? And if there is, what parts are they ?


wiring harness, distributor, suspension(maybe), and probably the transmission. You’d be better off getting the chevy 350 with the 700R4 tranny swapped in there. They’re cheap, plentiful, and have tons more mods available for them.


if not a v8, why not a turbo v6. I’m not sure if the engine in your car now is the same one they used in the Grand National(GNX), but you could do that as well.
However, the most crucial part of the swap is this; if you do not know what you are doing, TAKE IT TO A MECHANIC THAT DOES. It may cost more upfront, but having it done right the first time is better than going in and out of the car having to redo everything


IIFC, the Buick Regal had the transverse mounted 3800 series engine.


Not in 1981. It was RWD!


Anything made in 1981 is not worth the price of a set of plugs, let alone an engine swap…


Welllll… paying a mechanic to do an engine swap will get pricey, fast. You’d probably be able to just buy a car with a big V8 for what it would cost just in labor. If you can establish a friendship with an indpendant mechanic, he may give you advice and you might be able to just take your car in for small issues, but doing an engine swap is really mostly for people who enjoy doing engine swaps.


It’s a very doable deal. The degree of difficulty is going to be determined by which engine and how much, if any, of the emission controls are used.

Going with the emissions you’ll have to change the exhaust, wire harness, ECM, etc. along with redoing a mile of hoses.

If you do not live in an emissions state then I would strip the stock intake off of the Olds 350, deep six all of the garbage, and replace it with an Edelbrock or Weiand intake along with using an Edelbrock Performer carburetor.

Dependable and as simple as it gets.

You’ll have to modify fuel lines, throttle linkage, exhaust, etc. but this is to be expected.


After all that, you will STILL have a POS 1981 Buick Regal worth $200 on its BEST day…


I am sure that you mean on its best day from now forward. it was certainly worth at least $200 new. Otherwise, well said.


This guy is going to be really upset when he finds out that you 2 experts on the value of vehicles tell him his 9 sec. 81 Regal is only worth $200.00.


This car builder chose this body because he could buy it for $200 AND it has a real frame under it. If it was labeled a Monte-Carlo, he would have had to pay MUCH more for it…


Actually the purchase price on the car was $875.00. He was able to limp the tired V-6 home. He has spent some where around $20,000 on it since then.

Your statement was “After all that you will still have a P.O.S. car worth $200.00 on its best day”.

So based purely on your own logic this 9 sec. 81 Regal is a $200.00 P.O.S. regardless of how much money or time was spent on it.



Putting a V8 in a car originally equipped with a V6 requires new front coil springs as well, the radiator will be too small in all likelyhood, and other items (shroud)will be needed. On car that old, some parts can be obtained at a recycling yard. Engine swaps normally end up costing much more than originally estimated. Make sure you have some extra $$ in your budget.


What’s the difference between an '81 Regal and an '87 Grand National?

Black paint and a turbo V-6.
The question is not about the value of the car; it’s about performance, and I guarantee you a well built 350 Olds powered Regal will be worth more than 200 bucks.

Of course the OP could go in another direction and beef up one of those desireable and highly valuable 1981 Datsun 200 SXs or a '79 VW Diesel Rabbit.


Here’s an 80s era, 200 dollar piece of American junk; that also happened to beat a Dale Jr. sponsored Camaro at the time; and doing it in cushy comfort at the same time.

11.80 at 118 - not bad for grandma’s tank and my feeling is that this car could not be purchased for 200 bucks.


Well said OK4450!



This doesn’t look like the 4100 V-8 that is supposed to be in that engine bay.


That 4100 has gone through a “minor upgrade”, and if not done already, is going to go through another - near 9 liters of Caddy this time.

Here’s some more on Mr. Schwartz, and being a Mopar fan myself take a look at the Dart.


The worst cars Detroit made were made in 1981…POS, all of them. Sure, you can pour $20K into one and have a nice car that MAYBE, just MAYBE you could sell for 8-10K. The OP wants to DRIVE this car as transportation, not haul it around on a trailer or make parking lot furniture out of it. You CAN make a silk purse out of a sows ear, but why bother? Now, shall we talk about smog testing an '81 with a non-factory engine?? I’ll give you $200 bucks for it…