Hey, I was looking at some trick flow and other company top end kits, with heads, cams, some intakes, some had no cam and a suggested cam, etc. Trick Flows seem to make some good powerbands with the dynos they have listed, and they have ones relatively cheap into the 400hp range. They say minimum of 9.5:1 compression, but they dont really say what else you would need for the block. So what what i need to do to the block etc to prep it for that kind of power output? I already have a 4 bolt 350, what can i get done to it? Do i need a new crank and rods to support 10:1 compression and 6500 ish RPMs? Will i have to take it to an engine shop, and what kind of machine work would need to be done? Or, what if i bought a rebuilt or new block that was already 9.5:1 or so, would that hold up the rpms and high compression ratio? For information: This is going to be a 80A% track/20% street build, has to run on high octane pump gas, and its going to be in an auto, so I still need some torque low down!! Thanks, Joe

 

I have been researching them as well, and I think you need to get new pushrods along with the kit.
As far as your block goes it is up to you. If the block you have has a crank and pistons already in it ask the machine shop if there usable. If not get new ones.The block would have to be machined and all that ****, just tell the shop what your doing and they should know what to do. I myself have been looking at Holleys SysteMax II Top End Kit.

 

The block and crankare strong enough to handle 400 HP. The condition of the block and crank will determine the amount of machine work required. When you approach 500 HP you should be looking for a block with 4 bolt mains. Whether you need different size push rods depends on the base circle of the camshaft you are going to get.

 

Even If they can handle it, will it make that power with stock pistons(low compression)

 

bump?

 

bump again? no engine gurus here?

 

Most likly the compression they are specifying is due to the camshaft selection when you start getting into higher lift higher duration cams your dynamic compression will drop making necessary to start with a higher static compression ratio. If you have lower compression you will not make the same power as a higher compression ratio. Can you use stock pistons to achieve the compression ratio? The answer is in some cases yes it depends on the head chamber cc and the piston, be aware though some replacement pistons actually sit ..020 further into the cylinder than stock further reducing your compression ratio. If I was to spend the money on the top end I would not use the stock type $50 piston set I would look toward the Kieth Black hypoeutec or somthing better I would replace the rods with forged scat I beams(I dont feel its worth resizing the stock rods when you can buy forged for close to the same price) The factory crank should be checked for cracks and turned and polished if necessary then balanced as a rotating assembly. The block pressure and or magnafluxed checked. alignments checked. bored. torque plate honed, new main bolts mains align honed(if required) decking the block this is where you need to make some decisions and calculations to achieve the required compression but stay within your octane tolerance, get the cam specs run some dynamic compression calculations which can be used to ballpark the octane needed(aluminum heads are a plus because they will allow greater compression before detonation)target you determined compression by head cc, stroke bore, head gasket thickness and piston relief/style and deck height. We could get into quench distances but it will make this more confusing I think. Pushrod length is detemined by the cam somewhat but also by the head. rocker arm, deck height it needs to be measured. One of the biggest causes of main and crank failure is detonation controll that and at 400 hp you will have a stout engine that will last.