ok this is just something ive been thinking about and maybe im off base on this, but here goes anyway.

an LT4 conversion with ported heads and intake along with a ZZ9 cam and other necessary mods makes really good power.

when it comes time to do the bottom end would it be better to just do a simple 355 or would a 383 be better? my thought is that a 383 with its longer stroke would take advantage of the flow capacity of the LT4 heads better than a 355. i know the cam will have a great affect on this, but would it be the deciding factor? i mean is the answer to my question simply which cam i choose?

also the intented use of the car is for street duty. some occasional racing, but nothing hardcore.

so what is everyones thoughts on this? thanks. Trey

 

You will always have more power capability with more cubes. I am not real sure what you are trying to ask though.

This should be discussed in LT1 Tech though, transfering-

 

i guess u've never heard

there is no replacement for cubic displacement

 

yes there is and just because you have more doesnt mean you have more power. the whole setup has to work together. sorry if i didnt explain it right but the typical there is no replacement for displacement answer isnt what im looking for nor is it the correct answer.

so anyone care to discuss this more? thanks, trey

 

I'd say the 383 would be best. You're in there already doing a new shortblock and a 383 isnt much more than a 355. More torque and lower revs would be beneficial on the street.

 

No replacement for displacement is true under this condition:

Both are setup for what they need, sure if you put awesome heads and a matched cam on a 355, and a hotcam and stock lt1 heads on a 383 the 355 will blow the 383 up, but you have to be speaking where they will both be built equally as well as the other.

 

why spend all that money and just put in a zz9 cam?

 

The issue of a 355 vs. a 383 CI motor is highly debatable. Both can actually output similar power, depending on how each one is setup.

With a shorter stroke 355, u are capable of spinning a motor to higher RPMs more quickly, when fully balanced of course.

With a stroked 383, the Torque from the extra stroke helps to create more power from a lower RPM, however, it requires much more balancing and blueprinting to spin to the RPMs a 355 is able to reach.

In essence, Cam and Head selection plays a very key position in determing the ability of a stroked/bored motor.

The choice of cam, heads, power adder vs. N/A, and compression are the things that mostly need to be configured around whether or not u want a 355 or 383. Depending on your opinion towards those previously mentioned aspects and also with consideration of ur personal goals, will help u decide what kind of stroke/bore combination is right for u.

 

Since the zz9 cam is hydraulic you will make more power with the 383 with equal valvetrain setups.