Repower or sell?

[Stacey]

Have a 1991 Converible we bought in 2017 and have had a blast with it cruising around town. It has the 305 power and is not fast, but comfortable and looks pretty nice. So I'm at that point to pull the motor and install a LS, or a more powerful 350/400 or just sell the car off and get something else. Neighbor said it would ruin the value of the car by installing a LS, but would make it really fun and fast.  Since I own it I can do as I please and if I changed the motor and when I die my wife would just sell it anyway.  She never drives it.  Suggestions are welcome...thanks

[mfg]

46 minutes ago, Stacey said:

Have a 1991 Converible we bought in 2017 and have had a blast with it cruising around town. It has the 305 power and is not fast, but comfortable and looks pretty nice. So I'm at that point to pull the motor and install a LS, or a more powerful 350/400 or just sell the car off and get something else. Neighbor said it would ruin the value of the car by installing a LS, but would make it really fun and fast.  Since I own it I can do as I please and if I changed the motor and when I die my wife would just sell it anyway.  She never drives it.  Suggestions are welcome...thanks

Your ‘91 Avanti Convertible was really never meant to be a ‘fast’ car… An LS swap would,  in my opinion, increase the value of your car… but you’ll spend quite a bit doing it, and the huge increase in power may cause other issues (adequate brakes?)

If the car were mine I’d probably overhaul the good old 305, if it’s getting tired, and enjoy the car for what it is…. Good luck!  Ed

[Supercharged2004]

Hi - I have a 2004 Convertible with a Supercharged LS1 - I love the car with all the power. But I believe in keeping a car as original as possible. I am no longer a speed demon, like I was as a kid. My son likes to push it. I Just enjoy cruising. I like them the way they were built. I would recommend in keeping the car stock and upgrade to a newer one. If you are looking for more power. I will never sell mine. I will leave it to my Granddaughter.  But if you are looking to sell, I might be interested. I like them stock. Just my opinion. Rich 

[plwindish]

I bought an ‘89 convertible that been resto-modded with a crate 383 producing around 400 HP, backed up with a 4L60E automatic overdrive transmission and a Ford 9” rear end with 4:82 gearing. Tires had 18” on front and 20” American Racing Wheels on the back. The rear gearing was too insane so I had a more sensible 3:55 set put in. The 383 is a drop in compared to going the LS route. I had the car for seven years and enjoyed it, deciding to reduce my Avanti inventory to. Just my ‘76.  The 383 used instead of the 305 would have made a lot of Avanti owners much happier with the power of their cars.

[Stacey]

plwindish I agree,  your red 1988 looks great, I also changed the rear gear to help with the poor get up and go. Switched to 3:73 Posi, helped some, but still not all that much fun to run around in. Going to a 383 would be a lot less expensive and just as fun as a LS.  It would be a drop in too, with no major work to pull the 305 and drop a new one in. Don't know what I could get for it should I decided to sell, there are VERY few 1991 convertibles 7 or 8 or think. The fellow who owned it before me said it was the last one made, but i'm not so sure about that. It sure draws attention on every drive, gets thumbs up and smiles.  Thanks for telling be about yours.

[aardvark]

An LS Swap might be a real headache as well as a costly way of gaining HP.  It is NOT a clean swap. I would opt for a Chev SB of a larger cubic inch since the dimensions and connections are the same. An LS is a different ballgame.

[Geoff]

Stacey, I really like your convertible. It's a sharp looking car! I can also mentally picture it with a custom removable hard top affixed. That might be my Miata driving days coming out to say hello!

An LS-swap sounds incredible and the LS/Vortec family of engines are so common they may be had for reasonable prices. However, I completely understand the argument for gen. I and gen. II engines. If you have access to cubic dollars, World Products made an early block (Motown LS) which accepts LS cylinder heads. It also requires an LS cam because LS heads changed the valve ordering; no more 3,5 and 4,6 hot spots.

I know my uncle complains about the fuel capacity in the convertible Avantis, saying (tongue in cheek) he can drive it across town before having to fill up again. When I hear that statement an engine with cylinder deactivation could be a good candidate but there is added complexity associated. There is also switching to an engine of fewer cylinders, or engines from other makes, both of which open Pandora's box, all of which come with other chassis/wiring modifications.

I think if I had your car and was in your situation, I would remove the stock 305 and replace it with either 1980s L98 or 1990s LT1/LT4. You're in Arizona where driving enjoyment may happen year-round. A simple replacement keeps the down time minimal and the drive time maximal.

[mfg]

On 10/3/2024 at 6:16 PM, Stacey said:

plwindish I agree,  your red 1988 looks great, I also changed the rear gear to help with the poor get up and go. Switched to 3:73 Posi, helped some, but still not all that much fun to run around in. Going to a 383 would be a lot less expensive and just as fun as a LS.  It would be a drop in too, with no major work to pull the 305 and drop a new one in. Don't know what I could get for it should I decided to sell, there are VERY few 1991 convertibles 7 or 8 or think. The fellow who owned it before me said it was the last one made, but i'm not so sure about that. It sure draws attention on every drive, gets thumbs up and smiles.  Thanks for telling be about yours.

Your ‘91 is probably the most perfected of the GM chassis Avantis… Truly gorgeous vehicle!

[aardvark]

I've mentioned the complexity and with that comes excessive costs. but there is another factor. When the hood is opened a Collector is going to see a LS swap and think twice, whereas a same sized Small Block (like some have said a 383ci) at 400+ hp is the same configuration , thus looking the same.) Add to that Your adding modern day electronics in the mix... I'm doing everything in my power to go away from that..

I might add another perspective..... Many of Us want to Hop Up and Modify to the point of massive financial loss. How many times have you seen someone pour $$Cash..into a rebuild and at the end are left with a car that they will never recover their expenses back when the car sells? I can buy a LOT of Vehicles at $.50c on the $1.00 of what the seller invested.  I'm not into Collecting to lose $$'s..  We Avanti Owners are Undervalued as it is (which I really don't understand with the rarity of Our vehicles). To sink $thousands. into a rebuild that will never be returned at the end of the day, seems outrageous.  I'll say one positive in this whole realm... IF You plan on keeping the Car until Your Death and just want it up to Your Specs...Go For It !!

So do the math and figure if what Your after makes sense to You.

Edited October 7 by aardvark

[Desert Driver]

Bottom line - it's your money, so do what the heart desires. A 383 is a good alternative to stock, with probably fewer issues than the LS. But if you've had all the fun the car can provide...sell it with the stock engine and move on.

[Stacey]

We leave for the winter and will have the Avanti locked up in the garage, so once we return will decide on our course of action. Been looking at just buying a GM new 350 with about 350 hp that would bolt right in and would sure make the repower pretty simple. Or by then we decide to just sell it off. All these decisions make my head hurt...