compression or flow?

[Alxsmt]

well im not really shure what will produce more power. i have a 3400 with flat top pistons (would be 10.7:1) but with my 3500 heads it would lower it to 9.8:1, so my qustion is would it be better to use my 3400 or 3500 heads (with the 3500 intake plenums)? im also going to be using a mild cam (the 1006 grind) my goal was 10.5:1 but it doesnt look like i will be getting that with the 3500 heads

thanks

[SappySE107]

Did you get my email about that cam?

Flat top pistons would give you a lot more compression unless it doesn't come out of the bore any. The 3500 top end will give you better flow/velocity so I would go with them, even at the loss of compression. With the flow/velocity, you will be able to introduce more air and fuel to be compressed.

[Alxsmt]

ok, im not really shure if the pistons stick out of the block yet, but i was told hey WILL give me 10.7:1 with the stock 3400, so im asuming they changed the position of the wrist pin because according the the CR calculator it would be around 13:1... idk to me it seems like it might not be worth it because didnt the 3500 have only 10 or 20hp more? and it has more displacement, AND 9.8:1 compression (weird lol)

but i will use the 3500 top end then, i just wanted a 2nd opinion on that


BTW i havnt gotten an email back since you told me what cam u recomended. i did decide on the 1006 grind though, how do i need to order it since the store is down? (wont let me view the shopping cart)

thanks

[SappySE107]

Store should be working fine. Maybe delete your cookies? I have been getting orders and tried it myself even.

The 1006 grind isn't better than stock by much. 1hp. I wouldn't use it if I were you but if you still want it I will get it made.

[Alxsmt]

really only like 1hp??

how much power increase for the 1393 grind?

i will try deleting my cookies

[SappySE107]

Much better. 2hp at 2000 RPM, 24 hp at 6000 RPM, 22hp peak at 4500, which is the same peak as stock. .533 lift though so that would push LS6 springs. I would prefer to use the comp springs or machine the heads a little to give more space between the coils at peak lift. I really like the 1393 cam though for the powerband.

[Alxsmt]

ok, what would u recomend for the stock heads? i dont really want to buy new springs if i can help it. is the 533 lift after u calculate the 1.6 rockers in the mix?

also is there a cam with 1500-5500/6000 power range?

thanks man!

[SappySE107]

That is the cam but you will need new springs. Any cam will need new springs really. The 1393 cam is the best for that powerband. There is one just like it but .480 lift that is decent as well. Still need new springs but LS6 would be great as is then.

[Alxsmt]

hmmm ok, what does the powerband look like on the 480 lift? whats the peak power? IF i do end up going with the 1393 is there anything u can recomend that i do to the heads other than the springs?

[Alxsmt]

BTW i just deleted all the cookies and history and stuff, the store says there is a cirtificate error when i click on shopping cart