I found the re-ring kit on Sealed Power's site. Its part # 2056117M - $234.99 on Summit - no applications listed.

 

There is potential for P-V clearance issues with 2.02 valves and the lip of the dish on the stock pistons... though much depends on the cam in use. If you're spending good coin on a completely new topend for the motor why not get the right pistons for it?

 

Only reason I wouldn't is to save money on the bottom for the time being and put a 393 rotating assembly in at some point.

Do those pistons need to be pressed out at a shop, or can I do it myself on the bench?

 

Stock pistons are press fit. Need a press and a rod heater to do them.

 

Here is some additional information I just got from TFS -

The there are 6 versions of the TW heads in that 170cc intake runner size:

TFS-51410010-M61 - Twisted Wedge - Track Heat - 170cc Intake Runner - 61cc Chamber - Dual Springs - 7/16 studs - No AIR Thermactor port
TFS-51410010-M58 - Twisted Wedge - Track Heat - 170cc Intake Runner - 58cc Chamber - Dual Springs - 7/16 studs - No AIR Thermactor port
TFS-51410004-M61 - Twisted Wedge - Fast as Cast - 170cc Intake Runner - 61cc Chamber - Dual Springs - 3/8 studs
TFS-51410002-M61 - Twisted Wedge - Fast as Cast - 170cc Intake Runner - 61cc Chamber - Single Springs - 3/8 studs
TFS-51410004-M58 - Twisted Wedge - Fast as Cast - 170cc Intake Runner - 58cc Chamber - Dual Springs - 3/8 studs
TFS-51410002-M58 - Twisted Wedge - Fast as Cast - 170cc Intake Runner - 58cc Chamber - Single Springs - 3/8 studs

The 61cc chambers are good with stock pistons up to .550 of lift (but verify with clay). They strongly suggest using TW pistons on any of the 58cc chambers regardless of lift.

They also confirmed the pushrod lengths and said that the rockers sit a bit higher than stock (and also require "tall" valve covers)

 

Yea, I looked on Summits' site at the 5.0 topend kits, those too require pushrods that are about a half inch longer than stock. That's some long valve stems.

 

Im ordering my cylinder heads this weekend. Will the 351W make better low end with the higher compression and smaller intake runner of the 61cc/170cc heads, or the lower compression, but larger runners of the 64cc/185cc heads?

(I appreciate all the help here as well. I have learned so much from the replies to this thread, as well as others that I have read through)

 

There's not really much difference compression-wise in a 3cc chamber difference. Generally as a rule, the smaller runners would make more bottomend power.

 

So I built the engine over the summer, but buying a new house, and a temporary funding shortage (caused by the new house) caused some delays in firing it up.

The engine is now in, plumbed, wired, and ready to go. Ive filled it with 5w20 and some break-in additive (prob not needed on a full roller motor, but dont think it can hurt), and "borrowed" a priming tool from AutoZone.

I started priming the motor with my light-duty 3/8" 115v drill, and there was so much resistance that the otherwise good drill started to smoke and burnt out. I upped my drill to a massive two-handle 1/2" drill which was more than up to the task. Oil started to pool on top of the 4 and 8 rockers, but flow decreased going forward along both banks until I was getting about a third of the flow to the rockers on 1 and 5.

This is the oil pump I have: http://www.summitracing.com/parts/mel-10833/overview/

Two questions -

1) Should the pump have so much resistance that I burn out a drill? (keep in mind that the temp in the garage is about 35*F)

2) Should I be concerned by the decreased flow to the 1 & 5 rockers? (could this be caused by the engine being angled too far down in the rear - which I know needs to be corrected?)

 

Yes, I've smoked a Craftsman 3/8" drill trying to prime an oil pump. I also ended up using a 1/2" drill with a bigger load capacity. But I had to be careful, as i was using a 1/4" drive socket on the drive shaft; I was afraid I would crack that little socket.

Not sure about the reduced flow through the rockers. Can you pull out the pushrods to look through them for obstructions? If not them, it would be the lifters or the oil passages in the lifter bores.

 

No need to worry about the reduced flow, that'll be due to the position of the lifters in their bores. As long as there's oil flowing it'll be good. Roller motors need no break in additives.