340 replacement block.. with a roller cam?

W2-340 said

It's when the valve lift becomes really high (combined with extended high rpm) that you see problems with the 59* tappets. I use a .640 lift solid roller and i turn the motor 7800 - 8000 rpm with no problems on the local dirt track here in fairbanks.

And with a longer stroked motor you can build your motor around the cubic inches. With a good 410 - 416 - 418 you should be able to keep the rpms well under 7500 and make plenty of power.

And to the OP, comp cams have come out with a solid roller tappet set made specially for the new 340 replacement blocks.

Click to expand...

Not true! Those replacement blocks still have the extra head bolt bosses in the valley for 6 head bolt heads like W8-W9 and Indy's as well.
I helped design those lifters Comp now sells, and they will clear everthing in the block EXCEPT for the head bolt boss!!
You will have to cut or grind that boss...you can trim it down with a porting tool or just knock the majority of it out but be carefull as water sits just .200 behind the valley wall.

Once you do this, your smooth sailing. I can sell you those lifters far cheaper than Comp can when your ready...as well as a nice cam for your intended purpose.

Brian