my lt1 just hit about 110k on the odometer and i want to refresh the bottom end. There is a pretty big price difference between a forged 383 and a forged 355. im getting a heads/cam setup from lloyd elliot and i want the car to run 11s. is the 383 really worth the extra money or is a 355 fine

 

A 355 will last longer if it's your dd but a 383 puts out some sick numbers. If your goal is to get in the 11's it can be done with a 355. To get into the 11's your prolly going to need a new rear end or atleast beef up your stock one. A trans built to handle power with a 3200-3800 stall (maybe higher), heads, cam, new injectors, headers, CAI, etc. It gets expensive quick so just factor that into your budget and see which one would work best for you. And suspension mods. Suspension, stall, and new gears in a 355 would put you in the right direction. But, if it's not you DD I would say 383. Torque moves you down the line and a 383 has plenty of it.

 

But I highly doubt you can get there with LE heads. I like has work but you will need straight aftermarket heads.

 

LE heads will be fine.. There are a bunch of people making TONS of power with LE heads.

As to your original question, I couldn't give ya a good answer.. I'm stuck in the same position haha. 355 or 383 LT1... or LSx 6.0h.. Decisions Decisions..

 

You can with the LE2 heads but it would take a big cam to do it. I was thinking of the LE1 heads when I posted that. The LE2 heads never crossed my mind

 

Umm, an LE2 heads cam will make over 400whp, which is enough for 10's in a properly setup car.

There is no beefing up a 10 bolt, you need a 12 bolt, 9" or S60, period.


You don't really give enough information to tell if a 383 is worth it over a 355. Would you be buying a new crank in order to have a fully forged rotating assembly? Because at that point the 383 would cost the same amount of money. If you just want a dependable 11 second car you will be perfectly fine with an LE2/355 for a power plant, but theres more to racing than power

 

LE heads wont make it into the 11's


LE1 heads and a 23x/23x cam will easily make 400RWHP and go 11's if you are a decent driver. LE2 heads with the same cam will be around 10-15RWHP more.

Most people dont go aftermarket heads till they go 383 but some very heavily ported stockers will work well too.

Since you are building a new short block, build it well with forged stuff and throw a huge cam in if want to rev it to the moon and make mucho power. In general, a 355 can make almost the same power a similar 383 can but it will have to spin faster to do it. 383 has more streetable torque and can make the power with fewer revs.

 

How about a sig. with some basic info about your car? It helps if people know what your starting out with. wrd1972 knows what he's talking about, be carefull about some of the info you'll get when asking questions. For example, I have an auto with a SS3600 stall, and I'm still on the stock 10 bolt. If the car was a stick the rearend would have crapped the bed a long time ago. Oh, and I have 5 yr. old LE heads, before he had stages, and a cam designed to pass emissions if it had to. Runs high 11s with decent air, 12.0xs in the heat of the summer.

 

my car is a 97 lt1 automatic. i have longtube headers on it and a k&n CAI. Basically i just want to know if a 355 will get me good power and torque and put me in the 11s with le2 maybe le3 heads and his 230/234 cam with a yank ss3200 and 373s with the stock rear end

 

Sure it could. Use the stock crank, some good rods and pistons. Bump up the compression a little too. One thing to think about is your choice of converter stall rating. In your case, I'd run more like a Yank SS3600 or SS4000. It's still going to lock-up under normal driving, so you can have your cake and eat it too.

 

My next build, which I'm in the planning stages of right now, is going to be a single turbo fully forged 355. I want the 355 because I'd like to rev it a little higher and it will also be a tad cheaper. Plus I just like the idea of running on pretty much stock cubes. Beating up on larger 6.0, 6.2, 7.0 LSx engines with a smaller cube LTx will be fun.

 

Beating up on any LS motor is always fun. Not all of them run equal to all the hype that they get.

 

I agree, but it's going to be ultra sweet to see the look on a C6 Z06 owners face once the forged-turbo'd-355 is in.

 

Why spend all that money and try to run on a stock rear end, and probably stock transmission?

Spend the money on a built tranny and a rear end first.

 

Why not DD a 383? LE can be put in the 11's easily (as everyone else already ran in screaming).