toilet flange help!

I am installing a new toilet in the basement bathroom. The existing toilet hooked up to a 4" cast iron pipe. I've purchased a 3" PVC offset flange to fit inside the pipe - is this the right way to go? Should I be using something else?
any advice /direction would be greatly appreciated!

Thanks
Brian

Most plumbers would use the existing 4" flange.
It may have slots or notches for the closet bolts.

If you don't have a flange to hook to, you can add one over the top.
If you add one, you would drill the concrete and use anchors to secure it.

Thanks Terry. Is it ok to use a pvc flange on top or into the cast iron pipe? Do i need to glue it in or ??? As stated earlier (perhaps not that clear) is that there is a 4" cast iron toilet drain in the floor. I've removed the existing flange as it was completely damaged/cracked etc.

flange

Terry, wouldn't a lead and oakum joint be much better?
You don't have to rely on a couple of anchors, what ever kind they might be?
If it was my home, I'd choose a good old fashioned lead joint.

flange

You cannot use a plastic flange with a cast iron pipe. It will not glue into the pipe. You might be able to use a rubber gasketed "screw in" flange but they do not come in an offset pattern.

plumber1,

I've never installed a lead and oakum flange where I'm at.
I don't think anyone has done that around here since the fifties.
(Greater Seattle area)

On a 4" buried in concrete, since the purpose of the flange is mainly to hold bolts, we use a "flange repair ring" that can be installed onto the floor.

Here's a post I found from the old board:
"REMOVE OLD FLANGE- SPLIT THE SIDE OF EXISTING FLANGE WITH COLD CHIESEL N HAMMER.WEAR SAFETY GLASSES.REMOVE THE OLD LEAD , YOUR GOING TO WORK IT A BIT.ONCE FLANGE IS REMOVED , DETERMINE LENGTH FOR NEW FLANGE.DROP NEW FLANGE OVER PIPE THIS IS AFTER NEW SUBFLOOR INSTALLED.PACK JOINT WITH OAKUM LEAVING 1 IN. FROM TOP OF OAKUM TO TOP OF FLANGE.HEAT OLD LEAD IN LADDLE AND POUR IN JOINT. LET STAND FOR A MINUTE AND CAULK (peen) lead with hammer and chiesel. be careful" Outofplumb

flange

Also, if the floor is raised, cast iron flanges come in deeper/longer depths than the regular flange.
A good thing to have here in Michigan