SJs 66coupe

I have been working towards building a 302 for the Mustang.

Have the ported GT40's and most of the other bolt on stuff now.

What I am wondering is which is better to go with block wise, a roller block or a non-roller block?

I know where I can get a 70's non-roller for pretty cheap and it's in good shape.

I have noticed some people prefer rollers (or they seem to). However, I have a buddy with a '70 Camaro that runs about a 10 second quarter and for technical reasons above my head he pretty much hates roller blocks.

Any thought or opinions on which would be a better choice. Right now I can buy either so figured it was better to decide now instead of buying one and then having buyers remorse after the fact.

racin66coupe

if you can get a roller block, get a roller block, unless your looking for massive power where a high nickel block would be in order. but your not gunna get that kinda power with gt40's haha. get the roller block, its free HP

67mustang302

Get a roller. The only reason to run flat tappet is if it's a class racing restriction. Rollers are more reliable, make more power and don't have issues with modern oil like flat tappets do.

Starfury

Agree with everyone else. Roller 5.0's are a dime a dozen, and you'll make more streetable power any day with a roller cam. By the time you have to start worrying about block weakness, you should be considering a Sportsman or aftermarket block anyway.

rmodel65

get a roller, if you want to keep your 28oz balance though you can run an old crank and rods etc just have to machine the lip off the crank so you can use the modern 1piece oil seal(a big plus over the old rope style

SJs 66coupe

Thanks for the advice guys.

I am not looking for a monster strip engine but want a really solid 270 or so HP street motor...hence why I went with the GT40's, i.e. cost compared to aluminum heads. I could buy aluminum heads but on the street when would I realistically use the extra HP...

Will go with the roller and call it a day.

Deviousfred

I agree with everyone. Good choice.

Be sure to read up on this conversion. It is pretty straight forward but there are some very minor details that need to be addressed such as the dipstick hole that needs to be plugged on the side of the block.

guitarman376

This answer to this question may seem obvious to many of you, but what does "roller" mean? Does that mean it uses a hydraulic roller camshaft instead of flat tappet? I don't understand how the later "roller" blocks are different from the older ones with higher nickel content. Can anybody answer this for me?

Deviousfred

The roller blocks have taller lifter bores to accomodate the taller roller lifters. And it is also tapped for the "spider" that holds down the lifters in the lifter valley. And yes, they use roller cams. Converting a non roller block to roller cam gets quite pricey.

urban_cowboy

The term roller can mean one of two things.

1. Roller lifters (roller block has taller lifter bores as mentioned above)
2. Roller rockers

A full roller valve train has both 1 & 2 which limits friction in the moving parts.


Question for the experts, what Ford block require spiders and what block do not for roller lifters? I always assumed they were for roller lifters in a non-roller block to keep the lifters in place.