Rod length doesnt make a huge difference in performance but it does take a lot of stress of the crank, since it is farther in the down stroke before it begins to pull the piston down.

 

well i allready have the rods so i know most likely i will need a custom piston.

i just want this bottom end to be solid.

i know the title of the thread was 355 or 388 but i also tossed around the idea of a 3.625 cola crank to make a 370 but i dont know if they make a off the self piston. the reason i thought of that is becuase i know the 388 could really use a set of afr 277 or something and the stock heads would not hold me back persay but i could make more power. but a 370 might just meet in the middle.

but i just dont know if they make a piston with that CH

any thoughts on this.

 

Diamond, who makes a good piston, will do a custom CH for something like $50/set. JE charges quite a bit more, I think it was ~$15/piston for the last set I ordered. But not a huge cost in either case.

Rich

 

As far as I can tell, there isn't really any negative effect of going bigger. You're talking maybe a little more money. With more cubes you'll usually make more low end power. You can make any size engine make a lot of power, so you can't look at specific examples of what such and such 355 did. Why go through the headache of getting all this custom sized stuff? If you are just into doing something marginally different, well then ok cool more power to ya. Other than that, there are plenty of tried and true setups out there that have a decent price tag....

Jonota

 

if you want to use those rods, just run a 3.75" crank. as far as the heads go, to small is better then too big everyday. there are 3 basics as far as heads go;

1. you want your target flow for a given amount of power.
2. you want your target port cross section for a given cylinder displacement.
3. the higher the hp/ci the more port shape plays a roll then actual flow. ive seen heads that flowed the same, had the same port cross section area and cc'd almost exactly the same be 20hp apart because of the differences in port shape, especially on the short side radius. and as your hp/ci grows it becomes increasingly important. over 1.5 hp/ci port shape is critical. i would stick with lloyd for your heads. thats my $.02

 

I love my Lloyd heads and they make good power, I too would stick with him.

 

well I decided on a 383 for a few reasons. #1 being the extra torque down low where it will be quite noticable diff. on the street. #2 is the same power level as 355, but much lower rpm. therefore the eng. will last longer and not be soo taxed at the high rpms. less stress equals less breakage. #3, I can always go bigger w/the heads/intake later if I want to and it will respond. if it was a 355, it could still gain some with the same mods, but at an even higher rpm. theerfor takin away from its street manners.
something else to consider is there is more hassle/cost in a 383 then a 355. you have to clearance the block, as mentioned, but also dont forget about things like clearacncing the oil pan/gasket=more assembly time since you have to completely preassemble the eng. to make damn sure every thing has adequate clearance. for me, being my first time doin that, is easily where I spent the most amount of time. and on top of that, during the preassambly stage, I scored the cyl. walls a little and to be safe I had to have the walls rehoned a half a thou to take out the scatches.
in the end Im glad I spent the extra time to do it the way I wanted.

chris