By going with such a large over bore, your looking at some lack of durability. Im looking at building the 351w in my truck into a 393 stroker. Is there really that much of a power difference between the 393 and a 408?

 

I wouldn't think the power would be significantly different between a 393 and a 408
depending on how they were built. I do agree with being careful about how much
overbore you can safely do on a 351W. If I was going over .030 and was building it
for some power I would have it sonic checked.

 

30 over is no problem on the 5.8 block, it's when you get upwards of 60 over you're on borrowed time.

 

You are right Conanski. I worded my post wrong. What I was trying to say was if I
was going bigger than .030 over I would consider having it sonic checked. Do you
feel that most any any 5.8 production block would safely take a .040 overbore? I have
always limited 289 and 302 blocks to .030 but have never tried more on a 351W.

 

40 over is the max I would go on any block if you want a respectable lifespan, after that it's roulette it may last it may not.

 

i had an old mopar 383 sonic checked and i could have run 120 over and still had plenty of thickness for living on the streets. 80 over would have been max for any kind of power adder. you are right, 40 over is about max for long life on most motors.

 

okay so new development as of today...im getting a set of 351 cleavland edelbrock performer rpm heads. i cant pass up the deal im getting on them so i am running those instead.

 

It is possible to run Cleveland heads on a windsor block but it is not a direct swap. It takes a special intake and some modification to the head gasket. They used to have a write up on this in the Ford Racing parts catalog.

 

no i know you need to plut one water passage and tap another. these are complete with rockers and valve covers and like i said i can't pass them up. i may end up selling them but im getting these because of the price. edelbrock makes an intake for these swaps.

 

Im hoping your planning on building a HIGH revving motor if your actually plan to make use of these heads.

 

the edelbrocks are cast similar to the 2V cleavland head the flow about 200cfm and have 2.02 intake valves. plenty of bottom end, the 4V heads had something like a 2.19 intake and flowed about 300cfm. the only head to flow more was the police interceptor 460. stock obviously. they say the 2v heads made killer street heads the power band was nearly as flat as my first girlfriend...lol

 

These heads are only just getting into the appropriate range in terms of airflow for a 400 inch stroker motor, heads that flow 300cfm wouldn't be out of place and wouldn't necessarally make the powerband peaky.. depending upon the rest of the combo.

 

they have some port work done to them, i dont know how much as of yet. i'll know more in a couple days when we tear the motor apart. like i said the deal is insane and i really cant pass on them. i may end up selling them and get a set of afr's but i'll see what the machinist says about them. he did a hell of a job on my 390 in my highboy and i've seen his work rolling around the track here in town.