Jr22121

so, Ive got a 1987 Formula 350 Bone stock other than a Cat back exhaust. Immaculate 48K miles.
I am not interested in LS swapping the car at all so lets get that right off the table. Seems everyone i talk to just says swap it. Im not going to do that.
Also not looking to get into much internal work at this time.
Picked up an Edelbrock High flow lower intake and Runners that are surely going on the car. I am contemplating cam, rockers, rods valve seats etc. I am also not opposed to replacing heads all together.
Looking for some input on cam and head combos if I was to replace the heads and cam recommendations for stock heads.
Also Chip/Tuning requirements?
Willing to change the converter.
I am open to most things but would prefer not to get into bottom end and piston replacement.
Not Trying to build a race car just bring a little more power to the party. Who doesn't like a little more power?

Kingtal0n

Don't do anything to it at all. Drive it stock as possible for longevity. You trouble the engine with a bunch of aftermarket parts it will become unreliable and you will spend more time working on it and making forum posts about how to diagnose it than enjoying the vehicle. Once the factory engine dies, then you swap it if you can still get an 02-07 LS for it. Otherwise, out of luck.

Jr22121

I have no problems wrenching and repairing but i am not an engine builder. not looking for wild power, not looking for problem modifications. This car will never get an LS. It will remain relatively period correct.

Kingtal0n

Its not a good vehicle to learn on because you are learning antiquated platform that everybody already learned everything there is to know about and won't ever be replicated.

The engine and vehicle is worth more un-modded.

It isn't a good engine to modify because a factory 02+ engine is cheaper, more reliable, easier to tune, etc...

Don't use time effort energy money modifying an antique piece of artwork you could drive without all the wasted money and energy? No matter what mods you make the reliability will only decrease.
The power will never approach anything modern, even a factory 4-cylinder will have superior power to weight ratio. The vehicle is heavy, the setup is antique, its just a collectible now and you will ruin it with mods.

I recommend maintenance. Put a new air filter on it. Do an oil change. Put some new plugs and wires on it. Clean it, wash the engine bay. Oil everything in sight. And drive

SbFormula

IMO, don't touch anything, maintain it and drive it.
If you want to modify it, search the threads on TGO.... many did it before you. Lots of information. This L98 TPI mods topic has been beaten to death here on TGO. So we are not going to reinvent the wheel here.
Yes you need tuning, in fact, tuning alone will get you better performance. Problem is, who is going to tune it for you? Good luck!

EDITED:
Forgot to say: Steering brace (wonder bar) + subframe connectors and maybe updated front brakes. That's all I would do.

SbFormula

Exactly what I'm doing with this one:

Put SBC on it though... and with my own custom tune. Other than that, just fixing it and enjoying the time capsule.

SbFormula

@Jr22121

Post some pictures

Komet

As mentioned, there is a lot of information available about these kinds of mods already. The TPI is the limiting factor in the equation so pretty much any head that flows as well as a vortec or better will be an upgrade. The party is over at 5k so limit your cam duration to no more than 218 / 224. You probably want at least 110 lsa for a tunable idle. Those type of mods require a custom tune. If you do end up making more power, a better fuel pump and bigger injectors may also be needed.

Tuned Performance

iTrader: (92)

https://www.gmpartsdirect.com/oem-pa...shaft-94666492
affordable upgrade works well on stock tune but added air flow with base and runners might want to tune.

Thirdgen89GTA

iTrader: (5)

I would not recommend doing anything further than CAI, headers, and exhaust. TPI upgrades like TB, Plenum, runners...etc are a waste of money. Unless these parts fall into your lap, its not worth the time or effort for the pitiful gains.

The above mods can be done without really impacting the tune, every one will increase power and efficiency.

When you start getting into modifying the intake you will need a tune, and unless you are willing to spend the time to learn to tune yourself (and get GOOD at it) its just not something you should do.

Especially if you put a cam in it, that will throw the stock tune out of whack immediately. The same goes for heads. Both of these will significantly impact the airflow of the engine, and in turn mess with the fueling and timing.

Toss a complete 5.3/auto into it and be done if you want more power. You'll make at least 100hp more than you could doing every TPI bolt-on under the sun, and retain perfect factory drivability, and get even better fuel economy.

BadSS

If you're set on the Edelbrock TPI base and runners, spending a lot of money on heads that flow much more than the base and runners won't give enough extra power to be worth the additional investment. The Brodix IK180s would be a good match for what you're building and the pair is at $1128 (at Jegs, $1155 at Summit - they'll price match). The "problem" is both places only have one set and it looks like there's been a price increase and the new stock will have a $265 price increase.

https://www.jegs.com/i/Brodix/158/1021005/10002/-1 https://www.summitracing.com/parts/bro-1021005

Another good set of heads for the money are the AFR195 Enforcers, but the Brodix flow almost as much with a smaller volume intake and exhaust ports, making them more efficient and a better match for you build.

The cam Tuned linked is a really good cam for the money for a 305 or even if you plan on sticking with the stock heads. The earlier version of that part number was made by Crane and had the same specs as a Crane 2032 (214/220-112, .452/.465 lift), which would have been a decent choice. However, it appears the newer ones are made somewhere else, or at least not the same. Those that have actually measured the newer cams have reported them to be around 200-205 intake and 210-216 on the exhaust, .452/.465 lift, That's just not enough cam to take full advantage of a set of aftermarket heads,

I ran a 218/228-110 cam in a flat top 355 and heads that flowed about like the Brodix in an 86 IROC with a stock 88 5.7 TPI Memcal. It ran OK with no more than a bump in base timing and using an adjustable fuel pressure regulator. Later, I bought the equipment to burn my own chips and part throttle did run a little better with the custom tune, but it wasn't that big of a difference. I say all that because the cam below (218/227-112) should run even better without "having" to burn a chip for it. The lift, especially if you go with a set of 1.6 rocker arms (which I'd recommend), will put you in the lift range you'll need to be with the Brodix heads.
https://www.summitracing.com/parts/s...make/chevrolet

The main upgrade you'll need to do is, regardless if you do heads or not, is to go with a good set of headers and at least a 3" intermediate pipe to a good muffler like the Hooker Aero Chamber 21729HKR or MagnaFlow 12267.

TTOP350

iTrader: (8)

Basic mods would be to update the air induction setup to 88-89 style.
the E base isn't much better than a stock base thats been ported. For gains, have the ebase ported $$.
ASM have probably the best flowing intake runners ​​​​​​.
cam would be something mild that enhances the operating range of the stock tpi power curve.heads, skys the limit but i like the 195 range of heads for most miled builds.exhaust, dyno don has a pretty good set of headers and y pipe.so does American racing but its expensive. Stainless headers and Y pipe with AR setup.

jpearcy1

iTrader: (1)

IMO the reason most people say keep it stock or don't do any mods is tuning. The factory computer/ecu is dated and hard to properly tune these days. If you really want to do something I would start by looking into a modern standalone ecu like Holley, Haltech, or Fitech. After that things like a cam, intake, cylinder heads wont be such a big deal. It just comes down to what your goals and budget is.

SbFormula

Yes tuning is a real pain!!!

And also cost benefit. The more power added to the L98 = more $$$$ = have to modify drivetrain, suspension, chassis and brakes... and the famous tune = way more money $$$$. In the end it's expensive and not much expertise around. Plus you will still get owned at every red light. The LS route is becoming cheaper and more expertise around.

My grampy Malibu Premier 2020 2.0 T with 9s AT, and a simple tune from Trifecta ($500) is quicker than my '91 Formula LB9 T5, with all the basics mods, ever was. The basics mods are still quite expensive if you count labor (shorty headers, cat back, AIRS delete, tune, cold air intake, cooler stat, throttle body coolant bypass, air foil and under drive pulleys) which yields a whopping +40hp if lucky. The '91 Formula was loud and eye catchy but was getting its a** kicked by pick-up trucks and Civics. It gets old pretty fast! The Malibu is a sleeper that no one pays attention to, was very cheap to buy (from rental company), as lots of low RPM torque like TPI and is quite fun to drive.

Why saying all this? To put things into perspective. The money and time you are going to invest might not translate into more fun or better car. Just a somehow faster, louder and stiffer antiquated car that gets lots of attention and gets its a** kicked by a common newer Camaro, Malibu or even Cadillac.

jpearcy1

iTrader: (1)

All comes down to what op wants out of the car. If he wants to keep the sbc and still be fast/able to perform with newer cars its gonna take a lot of time, money and a well thought out build of the entire car.