Was the 400 out of a '71 Impala flat tappet or roller? I'd like to build a roller motor, but I guess if its flat tappet, it is what it is.

Minion

 

Has to be a flat tappet I'm pretty sure.... I don't recall any 400s having a roller cam, unless a retrofit one was put in. Maybe someone else knows for certain, but I am pretty sure no 400s were roller... especially not the one you speak of.

 

There werent any factory roller engines until 1987, so no its not a roller block. You'd need a retrofit roller setup for that engine.

 

I have a 400 in my 71 Impala Impala
Oh +2 = Big Block!

 

Right... definitely flat tappet, whether it's a big or a small block 400.

I have a roller setup in my 400 snall block; it's no different in that regard from any other pre-87 SBC. The "retrofit" roller system slides right in.

 

What is a retrofit? What does it include? How does it work?

Minion

 

What they now call "retrofit" is what all the rest of us had been using for all those decades before GM's engineering intern came in and did his junior project in the office, and they put it into production... it's far simpler and more reliable than the factory's Frankenstein, and of course, can be used in any block from 1955 to the present, with no modification whatsoever required to the block (unlike the factory's stupidity).

The lifters are joined in pairs by link bars to prevernt them from rotating; there's a roller thrust bearing between the cam nose and the timing cover to retain the cam; and the push rods are shorter, because the lifters are taller. Most people use a high-quality timing set, but any will work. All other components are exactly the same as with a flat tappet. No machine work or special castings are required.

 

Makes sense, thank you.

 

:sillylol: ROFL!!! Ohhhh..... it hurts...... :sillylol: :sillylol: :sillylol: :sillylol:

 

You wanna know something really funny? They copied the setup almost exactly from what Ford was using.

He's also right about the 'retrofit' thing, its actually something thats been around before GM even thought of roller lifters let alone using them in production cars.

 

Alright, where do you get this 'conversion kit'? I've looked on summit and jegs and both have ones for fords but no kits for sbc
Do I get them from gmpartsdirect or something?

Thanks
Minion

 

All of the major cam mfrs. such as Comp, Crane, Lunati, Utradyne, etc. have been making them for years. Look at Comp's website for example.

Don't waste your time with GM. They don't have what you want.