1970 block, newer GT40p heads, EFI help

[Js5ohLX]

Ok, I'm helping my friend turn a 4cyl into injected 5.0. The motor he has is a 1970 block with new gt40p heads. My concern is, can this motor be made to use roller lifters? If not, is there HO firing order cams for non roller applications? Any help would be appreciated, thanks.

 

[ECU5.0]

yeah, im pretty sure you can run a roller cam in it. like you said it just needs roller lifters. i dont think there is any differences structurally in the block. but i could be wrong. we need michael yount or some of those other smart guys

 

[Js5ohLX]

I know roller lifters will go in it, but you need a way to hold them from turning. That's where I'm a little concerned.

 

[ECU5.0]

yeah, if you get a set of roller lifters off of a 5.0 engine in a junk yard grab the little spider that connects to all of them..its just a metal piece that holds them. i think that is what you need

 

[Js5ohLX]

cool, I saw that, but I didn't know that it would work with all the fomoco blocks, thanks

 

[Michael Yount]

Houston we have a problem. The roller lifters are longer than standard flat tappets. So my understanding is that when you use them in an early block with a standard base circle roller cam it pushes them up too high - they interfere with the dog bones. So, you either need to use a smaller base circle cam (which lowers the lifters - the block will have to be drilled in the lifter valley so the spider which holds down the dog bones can be installed), or go with a set of aftermarket linked lifters (expensive). The cam you pick will determine the firing order. If you intend to use efi - you need to match the computer you're using to the cam in terms of firing order. So, a computer out of an HO (Mustang, Lincoln) will be needed to use an HO-based firing order cam. Clear as mud?

 

[Michael Yount]

double post

 

[Michael Yount]

Houston we have a problem. The roller lifters are longer than standard flat tappets. So my understanding is that when you use them in an early block with a standard base circle roller cam it pushes them up too high - they interfere with the dog bones. So, you either need to use a smaller base circle cam (which lowers the lifters - the block will have to be drilled in the lifter valley so the spider which holds down the dog bones can be installed), or go with a set of aftermarket linked lifters (expensive). And after you go through all that, you'll likely need custom length pushrods as well. The cam you pick will determine the firing order. If you intend to use efi - you need to match the computer you're using to the cam in terms of firing order. So, a computer out of an HO (Mustang, Lincoln) will be needed to use an HO-based firing order cam. Clear as mud? You'll have to talk to the cam companies about HO firing order cams in a flat tappet grind. Be VERY specific about the firing order you want and the fact that it's not a roller, if you end up going that route.