I would HOPE the lt1 could hit 400hp as a 350..... My car currently makes 385rwhp (at last dyno, probably more now that the clutch isnt slipping and there is a new fuel pump in there) which is 452bhp. I expect 400rwhp now.... ish, which is 470bhp or more since this is a land&sea dyno, which loads like a mustang dyno. thats nearly 500bhp from a cam alone, which is really not that uncommon for the ls1, and my cam isnt a monster like the MS4 or T-Rex...... even tho my cam scares some people with its specs, its a baby next to those, where guys are making 420rwhp on stock heads (albeit ls6 intake cars).

I know the lt1 heads do not perform like ls1 heads do. however I still would think a stock head lt1 could hit 400bhp if an ls1 can hit 470ish. P&P those bad boys and do a valve job and I would think the gap would start to close. 400bhp really isnt that hard to hit with a SBC.

Now, i will say this:
you can get about the same power out of a more radical cam/head deal, or a more mild cam/head with the 383. the 383 will behave itself better on the street, and you will have more of a sleeper since the car wont sound near as pissed off. 383 is in no way a bad idea, I just think 400hp out of one is an underestimate. 400+rwhp is more like it.

 

i said that on the first page spec! www.elliottsportworks.com and look up his LE2 package for the lt1. i wanna say it says 390-420 rwhp with proper bolt ons and the variation is the cam. you can make a pretty nasty lt1 if you want...depends on budget. and to the OP, you're worried way too much about how much the lt1 weighs compared to the ls1

 

True that is a good point. It is just that aluminum is better than cast iron block. Plus I hear cast iron heats up faster than the alumium would. But from what Specter said it would be a stright swap for a LT4 so maybe I do that, I know those got 305hp stock ratings compared to the LT1 stock at 275-285hp. I think my deal is that I kinda want a fast everyday car, but at the same time the LT1 I'm gettingalready has mileage about 170,000. So I figure run it for now and save up for the next engine and tune up from there.

 

DO NOT SPEND YOUR MONEY ON AN LT4 UPGRADE....you can spend less money and make WAY more power. you're not listening to us...if i were you i'd run that motor till it does and when it does...rebuild it. it sounds to me like you'd be a good candidate for a 355(little cheaper than a 383). then you put a head and cam package on it and you'll be more than happy

 

Sorry Spec. Maybe I should have elaborated. That's what I was meaning to point out.

 

i thought that may be the case. but u could probably be well on ur way to 500 with everything built right on a 383

 

i see most people at about 450 or so with a well built 383 NA...throw the juice at it and it gets crazier. lt1's can run...that's all i'm saying lol

 

Sorry i should have made that clear i was referring to wheel horse power. And of course you can bulid the heck out of the LT1 and make crazy numbers just like a LS1 but if you are talking about a mild head/cam set up with bolt ons and stock rotating assembly i would have to say some where in the 340-360 wheel horse power range would be correct. Going above that you are going to have a little rougher idea and a little lose in street maners. Going above that you could make 400 but as spec said you are realy going to start lossing what most would consider street maners but still be very street drivable.

 

Keep in mind we are talking about a stock rotating assembly not a built high compression 383. Keep in mind when you talk about H/C, gears, or stalls a lot depends on your definition of street drive ability. I would say for a daily driver thats bolted with a MILD H/C set up that is set up for street and track mid 300s is about right. See above post for my little brake down .

 

i would again say you're on the low side. plenty of guys on ls1tech are running lloyd elliotts LE2 package which is rated between 390-420. i'll probably go with his LE1 package which is rated at 360-390 or so