hello all,
Names Marty. I just bought an 88 formula tbi 5.0 and i have lots of questions if yall wouldnt ming answering them.

1. is the cam roller or flat tappet?
2. what are our cam choices, does all the old sbc stuff work?
3. is there any way to tune the tbi system or should i just go carbed?
4. is the tranny a 700r4?
5. what distributors are available if i do a carb swap? part numbers please!
6. whats the curb weight on these cars?
7. did they come with open or posi diffs?
8. if the tbi can be tuned what are any aftermarket tbi's available?
9. what rear gear ratios did these cars have stock?

Thanks very much,
Marty

 

Heya Marty, welcome!

I'd be guessing on most of your questions because you have an 88 FB vs. my 91 Camaro. (Although I think I would guess right on most of them, there are some different year/model breaks that can get tricky.)

Anyway, for TBI, I can point you to the "EBL FLash" system.

http://www.dynamicefi.com/EBL_Flash.php

 

1) roller
2) no. You can use the Ram Jet 350 cam, or the '92-'97 LT1 cams
3) the TBI is pretty flexible, stick with it for now.
4) yes
5) Accel 59107c
6) you're around 3500#
7) no posi with LO3 and 700R-4.
8) Holley has a 670-cfm TB, but that's not the first thing to buy
9) yours was built with a 2.73:1 gear.
Now, I'm gonna do another reply, this time answering what you should have asked, but didn't know to ask. give me a minute

 

you want more performance, that's fine. Start with a rear axle from a '90-'92 V6 / automatic Camaro / Firebird. that gets you the 3.42:1 gears, and the 28 spline axles. Then install a conversion-style locker, such as the PWT-1931-LR from www.summitracing.com
Next, get a dual-snorkel air cleaner from the '84-'85 carbureted 305 H.O. cars, whether f car or Monte Carlo SS. Then remove that little tin dam around the center hole.
Then start upgrading the exhaust system. Buy stuff listed as being for an '88 5.7L GTA. Start with the cat-back, then do the headers with y-pipe.
From there, you'll be doing cam, heads and intake. Forget porting the heads you have. Instead, either get started on a 350, or find some casting number 081 heads.
TBI is fine of you can be happy with up to 300 HP. If you need much more than that, then start thinking about a carb. But there's NO sense putting a carb on there with the heads you have.

 

i had no idea the tbi could support mods. will it have to be tuned? if so who tunes them, i saw a DIY setup up but im not a computer wiz. for example could a stock tbi hold up to a sbc carb intake with tbi plate and ported vortec heads? or would i need a tune? also is the holley a direct replacemnt unit or would it need tuning. i am in houston if you know anyone out this way that tunes these cars. thanks and sorry for all the noob questions but if you dont ask you will never know! i appreciate it!

 

No tune issues for the axle, air cleaner and cat-back. Pick a desired HP level before I can give you a fair answer to the rest of your questions. Are you wanting to keep up with the LS1 cars?

 

funny you should say that i had a bolt on ls1 2000 camaro that pulled 11.52's with a 1.51 60'! 10's on 125 shot. honestly i want about 240-280 to the ground once i have a 350. i have no idea what the 305's can do but ill keep it till it dies probably. my plans are as follows:

1. long tubes
2. carb swap/maybe
3. rpm air gap
4. ported vortec heads
5. cam
6. roller rockers
7. rear end

hopefully that will do it. could the tbi system hold these mods?

 

With custom tuning, yes. Again, make the rear gears your very first mod. Long tubes aren't worth the hassle on a 305. This isn't an LS1. And the available long tubes are an awful lot more hassle than you're prepared for after doing a fourth gen. But if you must, they're Hedman 68460s for $223.
Forget adapting TBI to the top of an RPM AirGap. Forget porting the Vortecs, you can't improve the intake ports with DIY efforts. I've tried it all, when I had access to a new SuperFlow 1020 bench with every option.

 

ok the gears will definately be first and probably a torque converter. so what would you suggest i do? btw i am getting long tubes becuase later down the road i am going with a bigger motor. if you were building a 305 what would you do. i wanted to go with vortec style intake and heads because they will swap over to another larger SBC. just seems like a carb swap would be much easier and definately easier to tune (if you know carbs) but again i am a noob to tbi the last 3rd gen i owned had a 406 that put out over 500 rwhp... i just think it would be fun to try and make some decent numbers with the 305. so shoot me some suggestions guys! i always thought 305's were boat anchors but hell its low mileage so why not..

 

so the accel 59107c will work on the carb con version? you said 92-97 lt1 cams. are you saying stock or can you go after market if it is made for 92-97 lt1. if its carbed i dont see why you couldn't put in a decent sized. but again im a new guy. just wanted to verify. also i was told on another site these ditributors will work when its carbed.

SUM-850001R
MSD-8362

will these work?

also say i wanted to stay tbi. is there a custom chip i can have burned. if so who does it. i called quite a few shops round houston and they all basically say you cant tune them and i should go carbed for less hassel.

also you suggested a posi unit. i have always had spools in my cars. will the work? they dont make a full spool for the 7.5.
Summit Racing SUM-730075 - Summit Racing® Mini Spools

 

The trouble here is that if you just put Vortec heads on an LO3, you get about 8.2:1. If you mill them to get the 305 up around 8.8:1, then your 350 or 383 will need some extreme-dish pistons to fix their compression. Such pistons are available, but you're better off going with 081 heads on the 305. If you mill them 0.030", you can have 9.4:1 with Fel-Pro steel shims.
By the time you figure how much the small bores hurt the flow of the Vortecs due to shrouding, you're better off just putting 1.94" intake valves in the 081 heads.

 

thanks for the info my friend. what ever happened to the s/r torquers 305s from way back. i never see them any more. if you know a plave that has then let me know.

 

You're gonna have to make your choice at some point. Carb, or TBI. The TBI system can work just fine up at 6200 rpm, but it's not gonna support much over 300 HP. carb has worse driveability, worse mpg, it will drastically shorten the life of the engine, and it goes rich at high rpm when it should go lean, so it limits power near redline. But it is cheaper and easier to tune.
Stock LT1 cams work fine with TBI and stock 081 heads.
If you're wanting a big nasty cam, then go carbureted. A big evil cam will idle rough, for a race-car sound, and make more peak HP, but your driveability will be gone.
With the LT1 cam, 3.42:1 gears and a stock or B&M TorkMaster2000 converter will feel surprisingly good. If you insist on the big cam, go 3.73:1 and a TorkMaster2400.
This is not an LS1. this is an engine with NO potential. And as long as you're trying to apply what you learned from your LS1, you're gonna have problems.
This axle is not strong enough for a mini-spool, but they do exist. I ran a welded diff, and having tried it, I don't tell others how to do it. Not that mine failed, it didn't. I pushed my '88 IROC-Z to 10.21 in the 1/4 mile with the welded diff. But it's dangerous and illegal.

 

You can still get them, but they're worse than 081s.

 

do you know of a good place to find the 081's? would ported 081's and a carb intake w/ tbi plate work well? basically guys i would love to stay tbi but i am horrible at tuning electronics. so witha decent flowing head and say an lt1 style cam, carbed intake with adapter would that work without tuning?

 

if i got a hold of a 350 short block could i put it in and used the 305 heads? i know alot of people who do this b/c it brings compression to about 11:1. if i did this would the tbi freak out? i know there are 350 tbi's out there? also what cfm is the stock tbi?