351 blocks

From what I understand there are some small differences, and a common conception that the 69/70 blocks are the strongest. However, it appears as tho all of the non-roller blocks are very similar in regards to strength and everything else.

I believe it was 94 that they swapped to a roller valvetrain in the 351W's.

Basically, I'd just concentrate on wether you want a roller or non-roller block.

BottleFed70 said:

From what I understand there are some small differences, and a common conception that the 69/70 blocks are the strongest. However, it appears as tho all of the non-roller blocks are very similar in regards to strength and everything else.

I believe it was 94 that they swapped to a roller valvetrain in the 351W's.

Basically, I'd just concentrate on wether you want a roller or non-roller block.

Click to expand...

That's it. Of course there are the SVO blocks, the Dart blocks... but if you don't plan on racin' too heavy don't waste your money.

The 90's 351 roller blocks can handle ~700HP if I remember correctly. The non roller will handle 850hp.

i don't think the non-roller block are all that much stronger than the roller versions really, either will easily handle at least 5-600 hp anything more than that and you realy need an aftermarket block.

the 69/70 blocks have a slightly shorter deck height than the 71-up blocks. 9.480" vs 9.50", the casting number you'll want for the roller block is F4TE, starting sometime in the mid 80's the blocks went to a one piece rear seal which is a definite plus. so the 92 block you are looking is a non roller but does have the one piece rear seal.

the earlier blocks typically have a little more meat in the pan rails and main saddles making them better suited to a 4 bolt main conversion but generally speaking you don't need 4 bolt mains with a windsor block although a main stud girdle is nice and there is a company making lifter valley girdles as well that will help keep the block from twisting and splitting but you really only need to worry about if you're making more than 450hp or so.

bnickel said:

i don't think the non-roller block are all that much stronger than the roller versions really, either will easily handle at least 5-600 hp anything more than that and you realy need an aftermarket block.

Click to expand...

You are probably correct about that. It's 'possible' to make 700hp, but reliability will be a BIG factor IMO. That's why I would lean toward the +500" motor; won't have to spin as high and will be more reliable.

Stock 351W's have large bearing journals and are not happy spinning much more tha 6,000 r.p.m.'s, so look to make max power around there. Also, although there are plenty of lucky people making huge numbers with a stock block, I think everyone is overestimating the strength of a stock block.

stock windsor block are plenty capable of handling 500hp and probably 600hp with not much trouble, of course we are talking about Flywheel horsepower here and NOT rear wheel hp.

DukeGnarley said:

ok, i was just looking up the cost for a hydraulic roller conversion.... and it's spendy. so if i want to run a roller cam at all i should probably stick to the roller block. Thank for the help guys, I was wanting to be sure that a roller would hold up to 500 crank hp before i started looking for one.

Click to expand...

A roller block is fine in the 500hp range. Go for it.

Roller blocks started in 1994 and are identified by the taller casted lifter bores. Not all 94' blocks are rollers so you have to be careful. Also some roller ready blocks came from the factory with standard non-roller cams. Your 92 block is nothing special and would require the special link bar lifters to go roller. Don't try to half ass by converting it and using a reduced base circle cam.

It is when you are pushing 600hp+ range that you would be better served with an aftermarket block. The 69-74 factory blocks can live in the 600-700 range, but you will need to worry more about the effects of cap walk so special main caps would be warranted--$$$$$.