your correct about the extra cost involved with the heads. But if we are talking strokers you will offset the head cost on the LT1 because the long block is cheaper to build than the LS1. Anyway don't want to get in a big LT1 LS1 debate it just boils down to personal preferance on what and how you want to spend your dollars to go fast.

 

I'm hard pressed to believe the LS1 block is weaker than the LT1. 6-bolt mains??? If there is a weakness to the LS1 design, it is the "4-bolt" per cylinder pattern on the head bolts. Not as strong as the "5-bolt" pattern on the LT1 and all Gen 1 SBC's. A lot harder to keep the heads on a blower or nitrous application.... just like a F*rd.

But the LS1 crowd has the choice of the regular LS1 block, the slightly modified LS6 block, the C5-R 7-liter race block, and a couple variations on the cast iron blocks, including the 6-liter truck engine.... and now they've added the 5.3-liter aluminum block for the SSR..... that's about 5 more choices than you get in an LT1 block.

Mark Montalvo, who used to post here regularly has built two different versions of a 421ci LT1. One was a 4.090" bore x 4.00" stroke, and the other was a 4.030 X 4.125" stroke. Neither was an inexpensive engine, but it can be done.

I've seen shops like Cartek and ARE selling 436ci LS1's, so apparently the early problems with sleeving the block have been overcome.

 

I read somewhere that World Products has a LT1 block that will handle 4.25" bores.... I dunno if it's true...

 

That would be freakin awesome.

 

i have personally seen a 414 ci lt1

the big ls1s are getting huge custom sleeves made

 

Yup, I've talked to the guy too. Although I've seen a nitrous'd 422 ci LT1 around here, I forgot who's it was.

You don't really need tons of cubes to make power, I plan on doing well enough on a little 355, with tons of spray.

 

IF you want to go big just go get a Brodix or World block and get a 400 block converted. It wouldnt be cheap probably then a resleaved LS1 block.

 

There is a guy in the fbody club that I'm in and he's currently putting in a 409 in his car. So far he says it's putting down 558HP/562Ft.Lbs. Should be an amazing ride.

 

There aren't as may big-inch LT1s out there as LS1s because we'll kick their asses without'em. Is that a good enough defense for ya?

LS1 the god of all motors? The LS1's nothing more than the god of my rearview mirror, and I'm not all that fast. My favorite is how all of these LS1s are turning high 12s and very low 13s in stock trim. Pretty funny. I've never seen a bone stock LS1 run faster than a high 13.6, and never will. I even went as far as to request dyno results proving all of these stock 300rwhp LS1s. All I got were excuses that "LS1 owners don't keep their cars stock" and "I've seen plenty LS1s dyno 300rwhp." And the ones that I didn't get excuses from had nothing more to say than "You're just jealous that you don't have an LS1!"

Guess what. I still haven't seen those dyno sheets or that miracle LS1 run faster than high 13.60s. I've just come to terms that I'll never see it happen.

To be honest, I've NEVER even considered an LS1. An LS1 may be faster out of the box, but let's see it go 12 rounds in the "ring of reliability." Once the mods start, it's anybody's ball game, and I'll put my money on the LT1 every single time.

BTW, I just applied for my new personalized license plate. It reads:

"LS WHAT"

 

One of my friends has stage II LS6 heads and a 224/224 cam on his 346 ci LS1.

He runs 118 mph trap speeds.

 

just got my new issue of Chevy High Performance magazine.......454 LS1 in there......

 

I had a 99 Trans Am, bought brand new, that I went 13.51@106.1 BONE STOCK with. Goodyear Eagle RSA's, paper air filter. Zero mods, and if I could have gotten traction, I could have probably seen a 13.3 or so. I have the timeslip to back it up.

 

yeah, darton makes the modular sleeves for the ls1/6 but they'll set you back some $1200 just for the kit. 4.03/4.06/4.125 all the same cost.
so while we're in dream mode just consider this... the block you have is good for more power then you are ever likely to see. the only time i'd consider a swap to something better is with force or nitrous injection and a plan to push over 1,000 hp at the flywheel. so, most of you should be fine. i made 470 rwhp with a solid roller 355. you shouldn't have much problem making the same power with a milder stroker.

then again it's better to set an et goal than an hp goal cause getting the power down is where it's at.

JB

 

Definitely some impressive numbers there. Nobody can argue that fact, but on the same token, I've got NO head-work done, nor do I have any porting/polishing work done. Nothing more than a "clean-up bore" from when the motor was rebuilt.

For sake of argument, let's say I went off and bought some big-*** AFR heads or something of equal comparison. Then, on top of that, did all the normal port/polish work and what-not. Isn't it VERY POSSIBLE to be trapping the 118mph traps also?

Also, keep in mind, that the mods I have done to my car aren't all that many. In fact, aside from the entire LT4 HC setup, which includes the cam, 1.6 roller rockers, and valve springs/retainers, all of my mods are pretty much direct bolt-ons. Obviously that's not going to include the 2400 stall either, or the shift kit, but I really don't have any "serious" work done to the car. I could also probably step up to around a 2800rpm stall, which I'm fairly certain would easily drop me into the high 11s, but I don't want something that wild. My setup is still on the conservative side, compared to a lot of other modified cars.

No doubt, I've obviously thrown a nice hunk of change into my car, but it's still just as streetable as it came from the factory. I'm curious as to what your friend's Stage II heads and cam setup ran price-wise. I KNOW I've got to have around $2500 in parts tied into that car, at least.

But if this car ran so well, then why did you get rid of your 1999 T/A for an LT1 car? From your SN I'm assuming you own a 1993 Formula or T/A.

 

Where did you get that???? There are so many stock bottem end 420+ RWHP heads and cam ls1's (only346 cubic inches) it's not even funny.

There is quite a bit of wrong info in this entire thread. New guys read carefully. I only have a few post, but I am not a "newbie" to racing. I also have an Lt1, but let's be real, Ls1's make power. I prefer my lt1 , since it is basically just sbc , and you have the ability to convert parts ,and get really serious , and make more power than any ls1 if you are willing to do that$$, but There are toooo many 346 ls1's making 420, 430, 440+ rwhp .

Many of them have pretty small cams on top of that. Many are running cams only in the 22x range and with 346 inches, and making "big" power ,because of the good heads. Where have you been?