Thread: 1981 malibu engine and trans swap

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I have the opportunity to pick up a very clean 1981 malibu for 1700. It is a six cylinder car . I have a 406 w/ tpi and 700r4 trans and gran national rear sitting in my garage . I have been searching for a donor car for 2 years and this car is perfect . How involved will the swap be . I was looking for an 8 cylinder car but I have had no luck so I really dont want to pass on the opportunity . My trans has the hurst olds shifters and I wanted to keep them but the car has a bench seat . What changes do I have to anticipate and in the end is it worth it or should I keep searching ?
What will be the steps I have to follow ?

This should be a straight forward swap if you can find a V8 car in a yard. You'll want to get the trans xmember and the frame towers for the engine mounts. Of course you could build your own xmember if you are so eqiupped.
Being that the Malibu is an A body and the GN is a G body I am not sure what the difference will be in the rear end suspension points.
A custom drive shaft will be needed and you may want to upgrade to a HD V8 radiator and shroud.
Mark

Ive had all of this done on my 79 T/A and it seemed pretty easy . I figured I would save some money and do it myself . With the T/A I had more money than time so I paid to get alot done . this time I have more time than I do money ..
I just wanted to make sure I am picking a car that will make the conversion as painless as possible . I called around to get a cross member and the I was told the V6 crossmember will work . If I dont want to use that one he said get the one from Jegs .

No real tips for the swap, But mailbu's are cool, is yours a wagon or just the sedan model, i picked mine up for 250 bucks and went completely through it from the ground up, chippin along at it but restoring cars is really great, this is my first.

Its a sedan . I paid 1600 for it . I have seen alot for less but as far as I can tell there is no surface rust . I figured I rather spend a little extra upfront them to have to buy quarters and put them on . i found a wagon but the whole rear quarter was shot . Do you have the bench seats . I think I want buckets but not sure which seats I can swap in . My trans has lightning shifters and I really would prefer keeping them.

I have alittle advice for you . first be carefull of car magazines . IMOP all they are all advertisements . Yes they have nice cars but the sell you on alot of products .
secondly dont be cheap . Do your wagon right once and you will get a life time out of the parts . a 20 year old part is cheaper but it has 20 years of abuse and sitting around . If you can buy new buy it new . Everything i have had to replace on my T/A is because I cut corners when I started running out of money . In the end it would have been better and cheaper to spend the money once . Go into to it with the mindset that you are going to do it right once and everything should hold up for you . Good luck .

The six and V8 rear X-members are the same. The GN rear will fit easily. I'd hold out for a 2 door, but its your choice.

I know I said sedan but I meant two door . I know a 350 would fit , which I have but I want to put in the 700r and thats where I am not sure . I really want a sleeper I can drive all the time . My T/A is knocking on the 12s but I dont want to make the sacarfices to get it there . It still has the stock converter and I think if I change the converter I would be solidly in the 12s . My problem is the car gets 8 to 10 miles a gallon no air . I will never get rid of the car but I want a few more creature comforts like AC and fuel injection and overdrive . Before the gas crisis it would cost me about 20 to 30 bucks to drive to work and back . I couldnt imagine how much it will be now .I am putting my wish list together now . Updated brakes , air ride suspension , PSt front end kit , ac system .,As I said those car magazines are murder on your pocket book .
any other suggestion recommendations or warneing on who and what to stay away from?

. dealing with Mondello for my T/A conversion , its has an olds 455 , was the best thing I could have done .

Very easy on these cars. The motor mount holes are already in the frame. These cars do not have frame perches on the v8 like old style. The motor mount is on the bottom,clam shell on the top.
Go to any parts store and get motor mounts for a v8. On the upper clam shells, get them at a junk yard or chevy dealer.

The 700 trans.
the rear mount is 4 inches farther back unless your car has a 200 4r in it. (I dont think they had those in 81). A few companies make crossmembers for this application. You will have to cut a drive shaft or make one. The 700 is longer.

Oh yeah.... the aftermarket crossmembers have provisions for true dual exhaust. I have done it both ways. In my previous cars I notched them out on the drivers side for the pipe. My current car has a G force. It is a nice piece and easy to use.

Get a v8 radiator and the upper and lower shroud for a 8v. I am pretty sure you can still get these shrouds new. bolt in.
If you are going with electric fans,dont buy a new shroud. just get a big radiator that fits and mount the fans.

I've done a '81 Malibu and '81 El Camino. The motor mounts are a bolt up deal, the rearend is too. I would pop for new rear control arms, try www.umiperformance.com. They have them at way cheaper prices than anybody else. The stock trans crossmember will work but will need to be modified for duals or from what I 've heard Gforce makes a crossmember designed for the 700 r4 and dual exhaust. As for your exhaust you'll need headers, I ran afterburners on my elco made for '78 to '87's. My Malibu ran headers made to fit an earlier Chevelle and they fit fine. Hope this helps.

I really appreciate the advice . There is nothing like experience . I paid off the car yesterday and found out that I bought it from the original owner . The motor I am swapping in has TPI with accel gen 6 computer . Should I replace it with Gen 7 or get a stock ECU . I was told to stay away from junk yard ECUs they are brittle .

Malibus like yours have nice lines,I've had several.If yours was a v-6,you already have the mounts, i'd go with the after market crossmember, boxthe rear control arms with bar stock. There should already be threaded holes in the floor for GM bucket seats.

Some of them have buick v6's in them...
These are the ones that you have to come up with mounts . The first v8 chevy conversion I did in one of these years ago was a buick 231. It even had the battery and fuel line on the other side. Yes, if it already has a chevy 6v in it you wont need to get mounts and upper calm shells.

Skybu , I see you have the 406 as well . Is your motor carburated ? My brother is trying to convince me to dump the fuel injection and go back to carburation . I have a 350 available but I read an article that said the questions regarding the 406 have become urban myth . He said there are numerous 400/406 out there with no problems .
I really wanted to go the fuel injection route its just 1500 for the computer and harness . I would still need to buy new injectors .
If I went carb I need the carb, duel plain intake and distributor which ball parks around 500. What is your set up ?
I have the seats from the hurst olds which would fit right in the are just the wrong color .

Originally posted by tzque
Skybu , I see you have the 406 as well . Is your motor carburated ? My brother is trying to convince me to dump the fuel injection and go back to carburation . I have a 350 available but I read an article that said the questions regarding the 406 have become urban myth . He said there are numerous 400/406 out there with no problems .
I really wanted to go the fuel injection route its just 1500 for the computer and harness . I would still need to buy new injectors .
If I went carb I need the carb, duel plain intake and distributor which ball parks around 500. What is your set up ?
I have the seats from the hurst olds which would fit right in the are just the wrong color .

My car is daily driver and it carburated.
I have seen some powerful 406 combos with TPI in books and on the internet but I do not have any personal experience. One thing is for sure. TPI's sure look cool. I put a chromed TPI on a freinds 40 coupe. Best looking motor I have ever seen.
From what I have read, the long runner on the TPI work well on 400. Mega torgue. lots of combos with over 500ft/lbs