Well today I had my first problem with the Camaro and i've had it for a month. She wouldn't start for some unknown reason, and suddenly I have a hole in the hose that goes from my Air Intake Hose down to my Headers. So with these two problems i'm coming to the conclusion that my little 305 is about to reach the end of it's life. Well probably not but it gives me an excuse to at least think about an Engine Swap lol. So guys what do you think LT1 the 275hp Legend or the L98 the 230hp Small Block that could. I like the LT1 for it's gas mileage, reliablity and well top end power but I also like the challenge of building up an L98. Let me know what you think I should do and btw money does play a role in this swap. Thanks Guys.

 

The thing to remember is they're both 350's, the LT1 will cost more up front but probably be easier to mod. The L98 is cheaper up front but will take more to run the same..I've seen LT1's go anywhere from $1500-$2500 w/harness and accessaries, and L98's about half that..but L98's are becoming harder to find while LT1's are plentiful at salvage yards. But you'll need more than just the motor and harness for the LT1...not sure what all..but it'll probably "nickel & dime you"...$$

With the right heads + cam + intake etc for each, BOTH are capable performers...
Owners choice...

 

L98 would be cheaper to find than an LT1... LT1 is pretty quick stock, but with the money you'd spend on an LT1, you could get the L98, and with whatever left over money you have, you can mod it up to out perform a LT1. all you need to do is change the intake on the L98 to that of, lets say, a mini ram, and you'll be out performing an LT1 any day. L98 are torque monsters down low, but have no top end. LT1's have good top end due to their intake... but like i said before, if you get yourself a HSR or MR intake to replace the stock TPI in a L98, you'll be eating LT1's but if you got an LT1, you could always convert it into an LT4... it'll run you almost 3 grand though if im not mistaken.

 

i foresee another "lt1 vs. l98" debate coming up...

 

I got my LT1 complete with harness and computer for 1250. I bought the rad and fan assembly along with it for not much more. I modified the harness myself and saved the 500+ dollars I would have needed to buy a Painless harness.

You can come out pretty cheap if you so chose. I went ahead and bought a CAI, Slp headers and full exhaust right to begin with.

I am not trying to start a war, but I don't think you could outrun an LT1 with the same money. Unless, you got a really good deal on everything you bought. I hear the L98s fall on there face after about 5200 even with an aftermarket intake setup. I have seen a dyno graph of a stock tpi 350. It made 320 tq and 230 hp at the wheels. The torque drops off pretty quick after its peak. The stock LT1s I have seen begin low AND stay high till the end.

Whatever you chose, at least it will be in a 3rd gen

 

That would be because of the heads. They don't flow real well after 5k rpms. All they need is a good port job and they will flow as well or better than stock LT1 heads. So HSR or MR + ported heads = an L98 that will kill stock or lightly modded LT1's

 

Uhh.... no. Its the INTAKE that is the problem on L98 engines. The heads are a close second. The aluminum L98 Corvette heads are pretty decent, but the iron ones suck. I dont think anyone is going to get 230 cfm out of an iron L98 head.

As far as the debate goes, you're asking the wrong crowd here. We're pro-TPI, so of course we're going to say go with the TPI engine. Either case is going to cost a lot of money, so pick the one in your budget that you can find easily. L98 engines are getting very hard to find.

 

Let me be specific here. The TPI setup dies at 4500. The heads die at 5K. So even if you replace the intake now you are limited by the heads. And there is a guy on here that got 248 CFM out of his stock ported iron heads.

 

If that is true about his heads, I would be REALLY surprised. More power to him!

 

The aluminum L98 Corvette heads are pretty decent, but the iron ones suck. I dont think anyone is going to get 230 cfm out of an iron L98 head.

Shouldn't be too hard to get well over 230 cfm porting a set of iron L98's. They are not a bad head to begin with.

Car Craft got 15HP more than a set of stock 882's on the dyno in their old 'Junkyard Jewel' series with a set of iron TPI heads. And 882's despite being from the smogger era flow better than the aluminum L98 head.

Intake port Flow @ 28" water:

882: 205 cfm @ .500"

L98 aluminum: 196 cfm @ .500"

 

Which would be cheaper to port, the Iron or Aluminum L98 heads? Would they flow the same, or would one out flow the other? Cuz i was thinking about porting out my heads till i get some aftermarket ones, but i have access to aluminum L98 heads, and my stock iron heads... i just don't know which one would give me more power if i port 'em

 

As far as I know, and I could be wrong, the only difference between the aluminum and the iron heads is the materials they were made from.

Same casting, only the aluminum heads are lighter, of course, and probably easier to work with.

Edit: I have heard that iron heads do flow just a bit better than the same aluminum heads but the few extra horsepower is negated by the increased weight.

 

LT1's, as much as I love them aren't where it's at. There is no market for them, parts are $$$ and there is no real advantage to picking one over the older SBC design.

I say, stick with the traditional sbc (L98), buy some decent AFTERMARKET heads (they are cheap, why bother with L98 aluminum SCRAP), carb it (TPI sucks) and go racin.

Have fun!

 

Everyone's gonna defend their preferences and choices made, which is OK. But just b/c everyone can't get L98 heads to flow, DON'T mean it can't be done..

The LT1 is probably one of the most owner modified smallblocks made, there's just so much, more info and more aftermarket for them than the L98 EVER had...at the right time.

**"So many misconceptions, so little time", as said many times; there are avariety of heads & cams in the L98's evolution.
It's just not good sense to group them all together in general. **

I've seen many of these heads apart and understand where the restrictions are. The bowls have a TON of room for improvement despite their already good performance I've seen an easy 25-30HP increase in just a good bowl-port / valve job on them.

The Vortechs flow slightly better "as cast" but once the TPI heads are ported right, they jump ahead. One drawback are the castings are thin, this doesn't leave a lot of room for runner enlarging. But raising and reshaping the runner entrances and gasket matching parts DOES make a difference.

**I am taking my time with porting my L98 heads,and will try to take pics and get flow numbers, before and after. And I'm consulting some very experienced "head-porters" who've assured me there's BIG gains to be had...(intake too) I'm gonna have less than $250 in my L98 heads, and am shooting for a 30HP increase in just the improved heads. I'm also porting the intake as everyone sees some potential in it too.

BTW my Iron heads don't "suck"...

There rated as 285/300 HP in the GMPP book, listing of heads. VERY close in almost every way(number wise)to the LT1's...64cc Chambers, 1.94/1.5 valves,straight plugs...I'm going to cc my intake runners this week...The Corvette's list at 163cc, and my iron heads are supposed copies....LT1's are supposed to be 170cc...
The main difference is LT1's are a "swirl" design, the L98's are a "Tumble" design...
These ARE facts, NOT hearsay...look'em up for yourself...

How are my L98 heads a big restriction??????

Also, the Intake was designed for the Corvette 350, it was simetaniously(sp?) slapped on the LB9 305, the VERY SAME PARTS....only the injectors were downsized to 19lbs from 22lbs...

Max lift flow numbers aren't where it's at, it's the mid range, where the valves spend most of their time...
230cfm is really more than a 350 needs, it would kill some throttle response and low end performance!...Which is why you see alot of smallblock heads promote, 190-210 range...

 

That's not true. SBC has 50 years of history, LT1 has 5 years at most. Don't be fooled by the 2 pages in summit that outline fuel pressure gauges and hotchkiss parts for 4th gens. Third gens have a MUCH LARGER aftermarket, because it is universal.

And regarding heads- the goal is to go fast. Why spend any money modding a stock head or a vortech head, if for the same price (or a little more), a true aftermarket head will outperform it with minimal work?? This is a no brainer. Just look at all the guys on this very forum that dump a ton of money into a motor and can't best 13.50's. In a world where every 4 door grocery getter now has 300hp, what is the point in modding a car to get 285? Sounds like a waste to me.

It's all about combo, and it's all about the heads.

JMO.