I had a 2400 TCI breakawy in a 3000lb S10 Blazer w/ about 330 chp. You would never know it wasn't stock unless you flashed it up to the stall. Otherwise, normal city driving was really unchanged. Once you get into the 3000+ stall area, that is when you will start to notice how loose the converter is and you will get some slip and rpm hang on slow to moderate acceleration. If it is a true cruiser, stick with a 2400 but if this a weekend warrior car that will see no or minimal long range travel or daily use, go bigger. Especially if you are going to spin it past 6k.

 

Thank you for the tunning suggestion, Kyle, I'll be sure to have a look at them when I get the chance. Though as far as my tires and gearing, I'm still going on the stock wheels and sizes of 255, with BF Goodrich Gforce Comp tires. As for the gearing last, when I checked the codes I remember finding that it was specced with the 3.07 gears from the factory I believe, it is automatic. The 3.45 gearing, I thought that was seen as a bit much for the L98 and that a 3.33 or slightly lower ratio would have done better for the car?

Moving to the intake as Vader suggests, then would it be overall a better idea to simply change from a FIRST intake to the TPIS MiniRam then instead:
https://tpis.com/products/1_man551?r...28342556950600
This would then cause a change in the cam that I would be choosing correct and move my power band higher, or Flatten the curve out more.
So if I were to move to an MR instead would the previous cam chosen still be viable with the 216 / 224 split?
https://www.summitracing.com/parts/crn-109671?rrec=true

Going to heads if the previous cam is viable its lift was .509 / .528 so choosing so it shouldn't then be difficult to find heads to fit that. These ones are a DART, with 180cc, 72cc combustion, and a max lift of 0.620:
https://www.jegs.com/i/Dart/301/1272...RoCyFoQAvD_BwE

Thankfully they are in my range for the purchase of two of them.
As for my search Id search specifically for my car 1987 Vette or engine L98, look for 180cc but often times it would turn up with 1986 and before due to the iron heads, or the 92 and on LT engine heads.

Now the car is mainly a daily and does from time to time see a bit of longer distance travel, so then that would mean that definitely I will not need anything bigger than 2400 stall and perhaps 2000 would suit my needs just fine.

 

216/224 would be fine for MR, or go with LT4 Hotcam Kit which is almost the same. Proven combo.

Dart 180s are good, try to go with a smaller combustion chamber. 58-64cc, not 72cc.

3.07 is perfect gearing for L98 motor or any L98-like engine, including SR and FIRST. When you go to MR, you've basically got a Gen 1 version of the LT1 engine, and it responds better to more gear. You would want 3.54 in a daily street driven car in that case, 3.73 if you only drive in town. Both fit the D36. 3.45s would be for the D44 case, I don't see you as ever needing that.

 

If you cam, gear, and stall for a shorter runner intake, it will always be faster than a longer runner intake. However, most street car owners have to (due to costs) or want to (due to preference) run a reasonably sized cam, gear, and stall converter. The smaller the cam, the lower numerically the gear, and the lower the stall speed it’s possible for a longer runner intake to run just as good if not better than a shorter runner intake – especially with wide ratio automatics. With the right combination the FIRST, even though limited by RPM due to the length of the runners, it can run every bit as good, or better than most dual plane, carbed, street 350s

You need to “cam” for the combination and it should be the last thing you decide on. Whether you go with a split duration and how much of a split determines on a number of things, such as the intake being used, exhaust flow to intake flow ratio, length and diameter of headers, and overall efficiency of the complete exhaust system.

I think the first thing people have to do is determine the budget and what they’re trying to do, which by previous posts sounds like you want a traffic light bruiser, and want to keep things within moderation as far as drivability and costs. I think the FIRST intake on a 350 is a very good choice for what you want to do – especially considering that you have 3.07:1 gears. I ran 3.23 gears and a TH350 transmission (8.14:1 multiplication) with a 3,000 stall behind a 355FIRST (which was similar to what it looks like you’re wanting) and it ran high 1.6’s in the 60ft with 26” ET Streets (high 12.5s quarter in mid 80 temps). Your 700r4 with a 3.06 first gear and 3.07 gears gives a better first gear 9.38:1 multiplication. So you wouldn’t have to change gears and still blast off the line with the FIRST. Just an FYI, I ran a StealthRam on the car also and it definitely needed more gearing and more stall speed.

Next, not that you have to buy this now, but you need to decide what stall speed you’re OK with. If you’ve never run a higher speed stall converter, you’re not going to know how they act and need feedback from those that have. I’ve install a number of converters for folks over the years that have ranged from 12” 2,000 to 8” 4,600 on the street - and tuned most of their cars with those converters to boot. Long story short, 2800-3200 is what I personally consider the best compromise for performance and drivability for a reasonably priced converter in a three speed automatic. With an overdrive and lockup, 2400 to 2600 is what I consider the sweet spot – if it’s a daily driver and you’re doing much highway speed driving. If it’s a limited driver or weekend car you can go higher (see later in the post).

Not all converters will really stall the advertised speed (typically lower for most street cars) and not all converters that flash/engage at the same speed will have the same efficiency. The quality of the converter makes a huge difference and this is one of those things that you usually get what you pay for.

This may be “at a later time” purchase but this is the least expensive lockup converter capable of stalling in the 2400-2600 range that I’d run. It’s a FTI rated up to 450HP - $499 from Summit https://www.summitracing.com/parts/fti-esrl3380

It’ll cost you the same money plus a reasonable amount for shipping, but I highly recommend calling them directly ONCE YOU’RE READY TO BUY and purchasing from them. They will do a custom stall speed (2400 up to 4000) to match whatever cam/heads/gears combo you end up with at no extra cost. Talk to them about your car and driving habits and listen to them on how high you can go for the type driving you’re doing – it will more than likely be higher than you think.
https://www.ftiperformance.com/Econo...-4L60-ESRL.htm

They also have a reasonably costed billet one for $830 plus shipping and would be well worth the upgrade if you see yourself going with a wilder engine combination later. Spending more up front can save you a ton of aggravation and money later.

As for as heads, man, there are a number of good heads available out there but not many for center valve covers. They’re another one of those items that you usually get what you pay for (or should). In general, 195cc heads are not “too big” for a performance 350. There are 195 and larger heads out there that are more efficient and are higher velocity (CFM of flow per CC of volume) than the stock heads you have on the engine right now. GM has been running larger volume, higher flowing heads on the LS engines for years and with the tuned LS intake they have no drivability or throttle response issues. You won’t either with the FIRST and a good set of 195s.

I think the best bang for the buck aluminum head right now are the new AFR 195 as-cast Enforcer heads. High quality USA castings and machining, angled plugs, with good components, and hydraulic roller springs good for up to 0.600 lift.
https://www.airflowresearch.com/195c...cylinder-head/
$953.30 for the pair from Summit - https://www.summitracing.com/parts/afr-1006

If you go with a FIRST and the AFR heads, with the exhaust system you have, I’d call Comp and get them to grind the following lobes on a 110 spread with 2 degrees advance 108 Intake Center and 112 Exhaust Center. This cam will have the same overlap as the cam I ran with my 355FIRST. Its single pattern will be better suited for your FIRST combo and will be “better” than what I was running - while pulling the same vacuum as mine (18” at 750rpm once tuned). With your MAF system, it will run OK with the stock tune until you can burn a chip for it. With this profile cam you need to run 1.5:1 ratio rockers now but if you end up porting the heads later, just throw some 1.6:1 rockers on it.

13357 for the intake 278/223/145 0.548 lift w/1.5 ratio rockers
13357 for the exhaust 278/223/145 0.548 lift w/1.5 ratio rockers

This is a much better engine recipe than what I was running and I know you would be more than happy with the results.

 

While the idea of getting the MR to support future mods and really get the performance out of the car, I have to say I didn't think I would need to be swapping the gearing at least in order to keep the current feeling when launching the car. The other idea was I was trying to keep the total I spend as close to around $3,500 as I can at least in parts and tuning that is, and the idea of slapping on an extra $200 does concern me a little, mostly because I wouldn't have a clue on how to install the gears. Since I'm still relatively new to working on cars, I'd imagine I would be spending at least a couple hundred to have someone else install the gearing for me.

For that reason, BadSS build set up sounds really nice to me if it allows me to keep my transmission the way it is. The AFR enforcer heads did look great in terms of pricing, quality, and the performance I would get from them. I could always swap them to the Dart heads if they offer much difference in terms of performance, but the way that I see it the build layout is something I would be very happy with.

As for the cam split that SS suggested then my split would be exactly 223 in / 223 exh at 0.548 lift factory ratio, all on a 110-degree separation on the lobes. I'm not quite certain about the 2-degree advance, or 108 intake center and 112 exhaust center, you'll have to forgive me considering that I'm still learning all this information I haven't actually come across these numbers in any of my searches so I wouldn't know what they do or are for.

Anyways thank you for the help certainly gives me peace of mind knowing what my options, and that I'm choosing the best one for me and my driving style. Also while looking up videos of my car and other people's build I found this one with pretty much the exact one I would have made if I were to choose the MR set up.
1991 L98 with MR, LT4 Hot cam, and Magnaflow exhaust.

 

I know you typically see 112-114 lobe spreads recommended for EFI engines, but it’s the amount of overlap (effects vacuum) that matters. This is a good read to help understand cam basics and lobe spread.
https://www.hotrod.com/articles/cam-...ne-angle-tech/

I’ve thought a little more about your combo and dug a little deeper looking at heads one more time. The only other head that I think might be a little better for you than the AFR Enforcers (on a 350) are the Trick Flow DHC 175 Cylinder Heads (TFS-30210007). They are really nice 175 cc heads with 60cc chambers that flow just a little better than the AFR195 Enforcers but they’re $1520. That’s $567 more and I just don’t see them being worth the extra money. Plus that puts them within $200 of the AFR Eliminators and there’s no question the Eliminators are worth that over the TFS heads. So, for the cost, I still think the Eliminators are hard to beat for your combo.

The cam I recommended is a little bigger and different than most would pick for a “TPI” but the FIRST is different than a GM based TPI (including the aftermarket stuff). Split duration cams (less intake duration than exhaust) work well with single plane and short runner intakes. As one of its traits, the shorter runners “naturally” make peak power at a higher rpm and the “smaller” intake duration will still take the engine to higher RPM levels. A trait of longer runners is they peak at a lower rpm when compared to shorter runners. If you want to bump up the RPM a little higher, then you can run more duration on the intake side and/or less advance on the cam (2-degrees vs 4-degrees).

You don’t want to go overkill – there is a pretty quick point of diminishing returns. Meaning if you go too big on the intake side with a long runner, you won’t make up enough power on the top end compared to what you’ll lose “under the curve”. This was extremely problematic with the small diameter GM style TPI intakes, but not so much for the FIRST. Meaning you can run a bigger cam and actually see some benefit from it - not just on the top end HP, but on the TQ curve past the torque peak, meaning the usable power area under the curve. This is why with a decent exhaust system like you’re going to run, people can benefit from a single pattern and low split duration cam with the FIRST.

The 223/223-110 cam I recommended was spec’ed for the higher speed torque converter (2400-2600 min).It has the same overlap as a cam I’ve previously run in a 355FIRST (with stall).It won’t be “too big” for the rear/trans gearing, but would be a little much for stock stall speed. If you know you’re going to buy a stall, then I’d recommend doing the stall first along with the FIRST intake swap (depending on how long you would have to wait), then do the heads and cam later. This cam and the FIRST would also work fine on a 383 with more compression – all you would have to do is open up the runners to 1.85” to match the inlet port on the intake (and maybe get the Enforcer heads ported).

If you’re not planning on getting a different stall, then you’ll need a different cam. I’d still put it on a 110 spread but would put the intake center line at 106 and 114 ECL (4-degrees advance built in). It should work OK with the stock stall but won’t ET nearly as good.
Intake - 13356 – 274/219/141 - 0.548 (1.5 rockers)
Exhaust - 13356 – 274/219/141 - 0.548 (1.5 rockers)

On a side note, I highly recommend opening a separate account and putting money in it until you get ALL the money to do EVERYTHING at once. I can’t tell you how many times I’ve seen people buy something, then for whatever reason have to sell it at 50-cents on the dollar. Or, start installing parts and get half-way there and can’t move forward and they end up with a mismatched car they don’t like driving and can’t sell, or have to take a beating on it.

Anyway, good luck on whatever you decide. EKG