What do you guys think the safe RPM limit is for a 71 350 block w .040 Speed Pro Cast pistons and stock crank/rods. Has all ARP hardware and is blueprinted and balanced etc. The reason I ask is with my new cam/head combo it seems to never stop pulling up to 6k but I am afraid to rev past 5500. The top end can handle whatever I can throw at it but I dont know about the bottom end. I do not have oil restrictors but I do have an HV pump and oil cooler.

 

I spin my cast bottom end up to 6k anything past that I would not recomend

 

Also the hv pump is no good at high rpm the olds design keep a lot of oil in the top end with stock pump with a hv pump you will suck it dry an extra capacity pan is a must restrictors as well

 

I know the 455 was blueprinted right from the factory back in the day, and they suggested the Red Line was at 5K.

Not sure about the 350 (as i have one as well) it shifts at around 4500 RPM. But then again, who knows if my tach is 'that' accurate.

-Tony

 

Coppercutlass & Tony thanks for the feedback, I learned about the oil restricted pushrods, and restricters and HV pumps after building this motor :-( Not knowing better I followed my old SBC methods. I am going with a larger pan soon, already installed a front mount oil cooler with remote mount oil filter so system holds 1qt more just to fill the hoses and cooler.

 

I made the dumbest mistake ever... well close... I used 5/16 pushrods with 3/8ths guideplates. Roller rocker slipped off a valve thankfully I was just coming off idle and shut it down. 1 bent pushrod, valve OK ordered a set of 3/8 th pushrods with 5/16th tips and guideplates actually function. Guessing the 106 degree heat in my garage the day I setup the rockers had taken its toll on my mind. I got lucky I didnt drop the valve.
New ones are 8.280 lenght by 3/8 my old ones were 5/16 8.490 and were too long for the angle milled heads and decked block.

 

Oh man! Good thing you were just coming off idle!

I've never had that happen (mind you i've never modified the inside of any engine i've had in the past either), but keep us up to date, did you grab any pictures?

-Tony

 

I got a pic of it after I fixed it with 2 of my spare big block chevy pushrods to nurse it home.

The new full set of correct lenght 3/8 rods arrive tomorrow. I got super lucky the rocker was actually riding on the retainer and the lock off the side of the stem, bent the crap out of the pushrod too. I was shocked that I didnt have a collision with the piston or just drop the valve into the cylinder.

 

Superstingray77 - over the years I've found a way to eliminate what your picture shows as the gasket sticking to the head.
Whenever I do VCG's, I use weatherstrip adhesive on the gasket to the cover, and liberally apply wheel bearing grease to the head - gaskets last forever!
Works for me!

 

Thanks for the tip ill have to try it. I glued the gasket to the head with 3M Super 77 then lubed the valve cover side, my thought was i wouldnt have to drag the cork gasket across the top of the rockers to clear the booster,alternator or AC comp/box on passenger side and risk tearing or nicking the cork. Ill give it a shot on the new .250 thick rubber/metal/cork combo gaskets I just ordered in.

 

Since the engine was rebuilt it really depends on the clearances, piston to wall and bearings.