Cross roads on engine block - Machine Shop called

[jake2077]

Alright everyone, the machine shop called and said there was damage in my 302 block out of my 71 Bronco restoration. The block had been bored previously to 4.040 and he took the #3 and #7 cylinder to .060 to clean up some pitting and rust damage. I know there are two sides of thought on boring to that size and heat related concerns. There is still some pitting visible and he stopped before honing to let me know and ask if I want to continue. Here are the pics. I wasn't prepared to replace the block and piston heads and hoping for a vehicle that is going to be used rarely I could get away with this as is. Thoughts?

EDIT: The shop just emailed and said they had not honed the two cylinders but could hardly feel anything and believe it will come out.

 

[jamesroney]

Original 1971 block at .060 over? Stop wasting money.

Find a decent used 1985 and up 5.0 roller long block. You can store your original block in a shed.

It will cost more for pistons and machine work than a good used 5.0. It's not even a question mark for me.

 

[jckkys]

There wasn't a Bronco block just '71 302 blocks and a lot of them. So the most anal restoration could do no more. I don't even think anyone would look that far. An EB isn't a Vet or Boss 429. I agree if 0.040" over bore isn't enough, get another block.

 

[73azbronco]

that with 60 over, its used up, buy another.

I would bet most broncos had torino motors...

 

[BUCKWILD]

^^^^^^^^^ Get a new block a 70 or 71 will be fine if you are after proper year range. a 70 block could have easily been put in a 71 from the factory. If not to worried about the exact year any 68 or newer block will work

 

[Rustytruck]

get a new block once it is painted blue its a Bronco block. if you spent 3 grand building a motor and is nothing but troubles you will wish it was changed.

 

[BroncoJimbo]

FWIW my 351W was bored 0.060 over 20 years and 75K miles ago. No issues with overheating at all. Mostly it's just the opposite and it runs too cool.

 

[Rustytruck]

https://www.tapatalk.com/groups/fordwindsor/cylinder-wall-thickness-302w-and-351w-t3769.html

 

[tabyers]

69 302 0.060, 20 yrs old, same story, no trouble at all, go figure. I might have made different decisions if I were doing it, but it was in there when I got it. Can't they test it to see how thick is in certain spots of concern?

 

[SteveL]

My engine builder told me .60 over for a bronco motor is no problem unless
You're gonna be desert racing at high rpm for long distance. One of 351w he went .60 and it stays cool all day long in LA heat and traffic. Since you need a block good time to think about a 351w.

 

[73azbronco]

351 can take 60 over if done right.


Might be easier to find an explorer v8. Many would be hard pressed to tell the difference between a 302 and 5.0. Unless they know what a fuel pump is.

 

[fordguy]

Get a roller 5.0 from pull a part and be done with it. I have seen a bunch of 5.0 rollers with high miles and little cylinder wear

 

[Madgyver]

can your machine shop get you a good cam?
Most cam manufacturers says they are not available and on backorder.