I am by no means an expert when it comes to engines but I am trying to learn. I am debating on building a 350 for my IROC but I have a few questions. I do know that I want a roller motor but am having no luck at this particular time in finding one. I have an oppurtunity to get a '73 350 for free if I want it but I am not sure what is involved in converting this over to a roller motor. I know for a fact that I am going to have it done but I dont want to waste a whole lot of money on it if I can just go out and buy one for cheaper. I have heard 2 different answers, one is nothing but the internals need to be changed (which I find kinda hard to believe), and the other is there will need to be some machining done (which sounds closer). My question is what needs to be machined, and will it weaken the structure at all?

On a related note will I be able to use the crank from that motor on a roller motor or will I need a different crank for it? Hopefully that is all the information you need. If there is anything else just let me know and I will answer it to the best of my ability. Thanks in advance.

 

No machining is required.

People get immensely confused by only being familiar with the factory's hideous amateurish garbage. All the rest of us had been building roller motors for decades before the factory's summer engineering intern dreamed up that nightmare thing for his sophomore project, and it somehow slipped its way into production. What a joke.

All you need to put a roller cam in a pre-factory-roller block is a roller cam and lifters (duh), a cam button, and push rods of the correct length (usually .400" shorter than flat-tappet ones, which works out to around 7.300"). Absolutely no machining whatsoever is required to anything in order to use a properly designed roller system. The roller lifters in question are intelligently designed unlike the factory's stupidity which is rather failure prone; they are joined in pairs for each cylinder by a link to prevent them from turning. How simple. No block modification, no big stupid stamped sheet metal thing pretending to retain machine steel parts, no special castings.... too easy.

The crank does not care what the lifter design is. On the other hand, all factory roller blocks have the one-piece rear main seal, and a 73 block will have the 2-piece; so that crank won't interchange into the 87-up block. But that has nothing to do with roller cams as such.

 

So now what about intakes. Am I going to have issues mating an intake up to the block. I am actually thinking about going with the LT1 but I got to thinking that there would be some line up issues with it. What do you guys think about that? And then on to the heads would there be any issues with coolant passages/oil passages or anything like that? Again thanks for the help.

 

No issues. Intakes only touch the block across the front and rear edges.

If you use late model heads, then your intake will continue to bolt to them.

Heads have the same coolant passages and will all bolt right to the early block.

You will have to change your flywheel or flex plate to the older design, because the crank flange changed from the 2-piece RMS cranks to the 1-piece.

All accessory bolt holes are the same on SBC blocks from 55 up.

 

RB you are the greatest you just answered all of the questions that I had at this time. If there is anything else you guys think that I should know before diving into this please speak now. Thanks again for all of the info. That is why I come to this site.