i have a stock 87 305 formula witha 4bbl.
im giong to eventually build my self a 350 but for now i was wondering how much lift and duration of a aftermarket cam can my heads take

 

Your current heads in stock form won't take much more than .480-.490 I'd guess? Durtation shouldn't be much of a concern though that I could see.

 

.480 - .490????
Try .400 - .450
Those springs won't take that for very long, and if you had good spring you'd pull out the rocker studs. I don't recomend spending a lot of money on LG4's unless you are going to transfer it to the 350. Things like intake manifolds headers air cleaners fuel pumps etc. Just don't get carried away. If you put in a new cam, unless you have a two piece front cover you have to take off the oil pan or move it which may involve moving the entire engine. I don't know since I've never tried this before. If you do decide to run a big cam like that then you can't rev very high or you'll float valves, break retainers, keeper, rockers.

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'87 Bird 350 .060 over 700R4 + Lots more

 

Bull shi*
I had a lg4 with edelbrock rpm cam .510/.488 lift/rpm intake and a 600 carb and i beat that thing to 6500 rpms for 20,000 miles and then dropped in a 355.when i pulled the 305 it ran like a top. no smoke,started first turnover every day.

also on the cam change you can do it without ever getting under the car. you can pop the cover out of the oil pan from above without loosining the pan at all. Just remember to glue the cover gasket on with some trimadhisive first so it wont move during installation ------------------
84 Z28
78,000 miles
1970 350 ci 4 bolt chevy motor punched .030 over to a 355
stock 1970 heads with 1.94's and very mild porting
edelbrock rpm cam,intake, 750 4barrel
weisco 9.6/1 pistons & rings
edelbrock headers and catback (without the cat)
700r4 trans
3.23 rear (no posi yet)

[This message has been edited by Hanks1 (edited July 11, 2001).]

 

gotta say it, you don't know what you're talking about..

any LG4 engine is the exact same frigging thing as a TPI engine only 25 horsepower less.

it doesn't matter on the oil pan, you don't even have to loosen the front two bolts on the pan if you don't want, you replace the old section of oil pan gasket with a patch section in the timing cover set.

you should do it from underneath the car so that you can get the bolt holes lined up easier and make sure the new seal is on correctly..

dude, i've done this atleast 6 times without much trouble..

i highly doubt you'll start breaking rockers from a big cam, you will notice it will float the valves easily but they will float long before you break a rocker, generally you break rockers if your piston hits the valve..



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Webmaster: www.IROC-Z.org

 

and when donig the swap you SHOULD use a new timing chain..

get a double roller, and CHANGE THE CRANK SPROCKET, it'll definitely be worn.

you'll have to 'walk' the sprocket onto the crank but tapping in a circle around the outside of the sprocket until it's completely on

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Webmaster: www.IROC-Z.org