Hi, i would like to know how strong the stock LT1 Blocks are... how much power does it really take to break it. they are 2 bolt mains? (so i have heard) I am unsure of this. All I know is i would like to build a LT1 but i don't want to have to keep building them because i do not make a lot of money. I want to build one with around 400hp-450hp, I don't care if it is a 355 or a 383. Can some one give me an example of an engine making this amount... and an example of how much HP has ruined there block. Thanks

 

The block can handle 450hp no problem. Lots of people are running more power than that on here. As far as your question on the 400-450hp, do you mean at the flywheel, or at the wheels? 400-450 at the engine is only 340-385 at the wheels for an M6 car, which all bolt ons and a big or custom cam can get you. If you are looking at the wheels 400-450, then a set of GOOD heads with matching cam, or a 383/396 build with the same will get you there easily.

 

stock blocks of any make can take loads of power. when properly machined, checked and clearanced, they can make well over 1000 hp. the lt1 is none short of the rest of the small block legacy.

 

wow.... Thanks alot... they are 2 bolt mains though huh? Well i think the way everything is going in the car industry if i want my car to be worth something i will have to have it fuel injected at least to get some type of gas mileage.... I want to build an LT1 for my 1977 Cutlass Supreme.... and i do want lots of power because it is a heavy car. I was going to go carburated but i think it might be fun tyring it the fuel injected computer controlled way. What is a good idea for me to try to do all this? Where would you recommend buying the LT1 from.... and what if i use the stock heads and get them ported and polished will that be ok of trying to make this 450hp number... ( i will buy a cam and headers besides just that maybe even more) and at rear wheels would be sweet but i don't think i have that type of money... and i barely have a clue about how much this all is going to be. Thanks so hopefully some one can give me some ideas thanks again

 

Build a 383 with the LE3 heads and cam. They make 425-450RWHP on a regular basis.That would cost ya 7-8,000 dollars for the major parts and figure 1,000 for extras. That's just for engine,no bolt on parts included,headers,TB,FAI,converter,intake,etc.
That would be a basic long block.

 

You are right, the Lt1 block is a 2-bolt main. If you are going to build a head and cam motor you should be fine with the 2-bolt mains. Use ARP main bolts and it will be a lot stronger than stock. Good luck.

 

Might as well use ARP main studs.

If you want to take it over 500hp then 4 bolt caps and a better than stock rotating assembly should be used.

Bret

 

4 bolt mains can be highly overrated. they do their job nicely, but having a 4 bolt main is about useless unless you are making big power. so many people think it's really something to have 300hp and a 4 bolt main. i'd say 500-550 is about the stock limits of the 2 bolt with stock caps and arp studs...from what i have read, at least.