Hello,

Im thinking of dumping my craptacular 305 TBI for a 350 TPI in my vert, and i was just wondering if anybody had done a swap simply because the 305 is sloooooow, and wondered how the pickup was with a 350 TPI ?

 

Alot better. I swapped a 89 350 TPI into mine and it was night and day. The TBI was pretty weak in mine. I found a donor firebird that I got the rearend from also. Alot of the rs convertibles were a 2.73 rearend. Swapped to a 3.27 borg warner. Well worth the swap if you ask me.

 

I have a stock 89 GTA vert, the one time I took it to the track I ran a 14.9@93 but I know there's more in it. The 60's werent all that good and the car probably could have used a good tune up to get it running optimal as it had a slight miss. I figure it'd run a 14.5-14.6 without doing anything as far as bolt ons.

 

swapped in a 350tpi for a 305 tpi.

stronger but it wont blow your mind without head/cam/exhaust

 

The biggest thing I noticed was the torque. To me it dident feel like it pulled any harder, but the extra "get up and go" was there for sure!

 

Anybody put a LTR TPI zz383 in a vert? I'm wondering if the near 500 ft/lbs would put too much stress on the car. This is assuming all of the chassis bolt on's had been done.

 

I would personally put secondary Subframe connectors on the car at a minimum... I think Every 3rd gen F-body should get those especially if your going to get any power to the street...

The only thing I have considered with my 89 350 Vert is to put Vortec Heads, cam and Intake base on it, and leave the rest alone...

John

 

no, you can put as much engine as you want in there.. it'll twist like crazy without SFCs, but nothing ever breaks dramaticly.
biggest annoyance is with the twisting, the door latch and striker bolts wear out over time.


if i was doing the swap, i would opt for something a little hotter then a stock TPI... and ideally... an LS1/LS2. lol

 

I HAVE AN 89 GTA CONVT. WITH A 383 TPI ALL TPIS UP TOP MINI RAM ETC DART ALUMINUM HEADS ART CARR TRANSMISSION AND 370 GEARS..AMONG OTHER PARTS..ALL I CAN SAY IS FROM A DEAD STOP WITH THE TOP DOWN ITS SCARY WHEN YOU MASH THE PEDAL...AND THATS WITHOUT THE JUICE...IF I WERE TO DO IT AGAIN I WOULD DEFINITLY USE A FULL ROOF CAR...BUT WHATS COOLER THAN A GTA VERT?

 

After the first few bolt on mods to my vert, when it had a stock 305, I welded in MAC subframe connectors, put in a strut tower brace and a wonder bar. I wanted as much bracing as I could bolt on at the time. Now Im putting in a 6 point cage. I love the way a vert looks with the top down and roll bar visable!

 

CAGES ARE COOL ...BUT MY GIRL FRIEND LIKES TO CRUISE IN THIS CAR WITH ME SO AS FAR AS A CAGE GOES ITS A NO NO ...MAKES IT REAL TUFF TO TRY AND SNEAK THIS CAR ON THE TRACK AT THE DRAGWAY..NO CAGE NO PLAY..WHAT ARE YOU RUNNING FOR A CAM IN THE 383..

 

Right now I have a TPIS ZZ409 cam in it with 1.6 rockers. When I get back home from Iraq, I plan on swapping in a TPIS ZZX cam (same 1.6 rockers) and the new AFR 210 Eliminator comp heads.

 

YEAH I WAS RUNNING THE ZZX IN MY 383 FOR A WHILE ITS A GREAT CAM AND IF THEY CUT THE CHIP FOR IT U WILL HAVE NO IDLE OR DRIVABILITY PROBS..I WENT WITH A BIGGER CAM IN THE 383 FOR MORE RPM RANGE FOR TOP END ..THE ZZX CAM LOVE THE N.O.S REALLY WORK WELL FOR ME 10.90 ON A 125 SHOT ..WITH SLICKS OF COURSE

 

I swapped out the 305 for a new ZZ4 TPI setup, at the same time I swapped the auto for a new 5 speed, very pleased with the results.
I too would suggest subframe connectors and a three point front strut bar.

 

I put an aluminum headed 350 with a SuperRam in my car . . . I don't have SFCs and my car (when it's running) is scarier than hell.

I need SFCs and a small cage . . .

 

I went from a low power 3.1L v6 to a 350-375hp 383. Yeah I can tell the difference still need to get sfc's before I get too stupid with it.

 

I have a 91 RS convertible, 305 TBI(170hp) and an open, 2.73 rear end. Right now I'm just trying to swap the series 2 carrier and gears out for a series 3 posi carrier and 3.73 gears. It will be nice to see the effect gearing alone has, as well as having posi. After I do that I think I will try to find an LS1/4L60E to swap in

 

but its fuuuun......

 

Liquid..3.73 and posi upgrade will be well worth it, sticky tires usually help out that mod also.

A 350 TPI would be a lot more fun than a 305TBI. With an auto trans, minimal mods will get you smiling. 2800-3000rpm stall converter, M/T Drag Radials, and a 100 shot of nitrous will get you ahead of the LT1/LS1 crowd.

I did a 396 into my car, check my site. after 8-10 transbrake launches at 5000rpm, I'd suggest triangulated subframe connectors and more bracing in the car, whether it be a normal roll cage, or just a mini style roll cage that is tucked along the floorboards, also connecting into the subframes under the car. Something more than the 2 dimensional looking subframe connectors. Almost something like a double frame rail 25.X drag setup.

 

I'm in the process of doing a ZZ383/T56. 95% complete...just trying to resolve some vacum leak issues from the Superram. With some luck, should be up and running in a little while!

 

I am not sure what trans you have whether its the 5 speed or the Auto. IF you have the auto I recommend getting some upgrades to the trans. Although you should not technically have many problems with a stock trans I ran into some odd problems when I went to a 3.73 from my 2.73. 1) the shift points were way too close together, by the time I was going 25mph I would be shifting into Overdrive, the shift points were too low for normal driving, even under full throttle it would shift early.

What ever gear you get I recommend finding someone who knows about 700R4/4L60 calebration. I did and what a difference. STAY AWAY from shops who tell you to bring in the shift kit that you want installed, they might know how to rebuild a trans but they know squat about performance applications. Start calling and tell the person in charge how you want it to perform what you have already and if they say, no problem I can set you up and they are a reputable shop then go with them... I would send you to my tranny guy but he is in Flint MI. Basically I told him how I wanted it to shift, what RPM I wanted it to shift at and what speed I wanted it to go into OD. Considering he got it dead nuts the first time, I think he did a good job.


John

 

I did the ZZ4 TPI with a Tremec TKO (from the 700R4). I am running subframe connectors and 3.73's. Torque is a good thing but I should have run 3.23 or 3.4 rear ratio.

 

3ZMAN, why do wish you had the gears that I have instead of 373's, I am a little confused, because I want to go to 373's from 323. With the 700r4, you should still get decent mileage. sorry, I just re-read your post and seen that you had a tko. is it a 5 speed