Cleveland question

[72mach1]

The old mach's finally hit 80k miles, and the things back firing through the carb, I have a few questions and I hope some one has some answers!

1972 stock 4v heads, more than likly open chambers, hydralic lifters, torker intake, stock bottom end

1. whats the average price on the west coast for rebuilding heads, if it's pretty easy (it kind of looks that way, but who knows) I can do it myself.

2. what are the cheapest, easiest , or most effective upgrades I.E. different ratio rocker arms, roller lifters things of that nature.

3. Are there clearance issue's when changing rocker ratios? how much can you change before the piston eats the valve?

4. What else can I fix, look for, should be concerned about when a cleveland hits high miles? I dont have the money/space/time for a full rebuilt, I'm just trying to keep the engine from blowing, any other tips or tricks will be appreciated
thanks -Pat

 

[latamud]

try replacing the distributor condensor for the backfiring problem.

 

[Hack]

WOW, a '72 Mach with only 80k miles?!? Amazing.

You might just consider taking the car to a good mechanic for a tune up. Backfiring through the carb could be a timing issue. Since you are short on cash, I'd suggest you start with that. With only 80k miles, you shouldn't really need to dig into the motor at all.

If you do decide to replace things, the original rockers and original two-piece valves are crap. I would say that they are the first things you should replace. Roller rockers aren't necessary. Sorry, but I can't recommend part numbers.

 

[ashford]

most all clevelands iv seen that have given up the ghost was due to burnt up ehaust valves and seats. so most likely hardened seets will be needed and also valve guides.
stock rocker ratio is 1:7 on clevelands and i havnt seen any higher
definatly install arp rod bolts.(sad storythere)

you could also do the oil pipe to the rear of the engine addon

 

[72mach1]

Thanks guys, I'll let you know how it works out.

 

[D.Hearne]

As for your back firing problem, remove the dist cap and while using a breaker bar and 15/16 socket, rotate the crank with the bar. Notice how far the crank rotates before the dist rotor moves. Chances are if your motor's never been into, it's got the POS nylon coated "silient drive" timing set and the nylon has broken off the aluminum cam gear, which will ( if not already) result in jumped timing. As for the rockers, I've got a better stock set from a 370 truck engine available ( cheap) These are heavier duty and have iron rocker fulcrums where yours are aluminum. The ratio is the same, all the Clevelands, Boss 302,351M/400 and 370/429/460 engines used the same rockers.

 

[72mach1]

As far as the distributer goes, it has an early mallory electric ignition, simailer to the pertronix, what about that? should I spend the 60 bucks to replace it with a pertronix, or pertronix2?

 

[D.Hearne]

I'd check both that and the slack in the timing set first. Like I said, if it's got the original silent drive timing set, it's likely jumped time.