I have played with those LM1's quite a bit in the 80's. Easy to get 300hp from them but to get 400hp out of them requires you to replace everything except the block. Believe me, your best bet is to find a motor that someone built up and no longer wants. You can usually get them for half the money that is in them. Then take it to your most trusted engine shop and get them to do a tear down-rebuild for under a grand. You will save thousands.

 

Please tell me what he needs to change in the shortblock and why. What about the crank, rods, and pistons needs to be changed to make 400 hp?

 

Thanks i feel like a dumbass for bother you guys i just started you know so im not too skilled in this sport yet, But i did some research now and i think i have a good shot at the hp if not ill just swap out to forged pistons and juice the hell out of it lol just kiding. Anyway thanks for the help ppl. I looked at the parts on the crate motor from edelbrock saying they have good pistons from the zz4 block so im gunna go with eagles rotating kits for my block and the chambers are alot smaller on the edelbrock heads so yea im gunna also go with the top end kit frome edelbrock there around 1700 bucks so im gunna back that 400 hp up with a beefed up trany and change my rear end to a posi with a 3.73 gears to get a good top end as well as hole shot

 

There is nothing wrong with beefing up your shortblock and throwing on some juice, but if you do that you better be planning on more than 400hp or your wasting your money.

And don't apologize for asking, go back and read my first few posts, we all started somewhere. If you don't ask you will never learn.