i picked up another thirdgen the other day,a 1985 camaro SC, with the 305 from a blazer. its a 4bbl. what are the major restricting parts of this motor?

i am gonna definatly get some headers and true duals, but what else could i get for relativly cheap and free up some good power?

i think an intake manifold may be in order? i should be able to get an aluminum one for about 50-100 used. worth it?

how bad are the stock heads, and intake mani.?

i am pretty sure its much the same motor as the LG4, if not exactly?

what would be better, a dual snorkle, or a open filter just sitting on the carb?

 

I would definatly do an intake manifold. I dont think i would do ture duals tell you really need to cause you do need some back pressure. I Would probably go with the dual snorkel even though i decided for the open element.

 

for that engine, 1 5/8" primaries with a 3" cat back using the crossflow muffler design will be fine (aftermarket cat back).

And no, you do not need back pressure. You need delta pressure. back pressure is the resistance that exhaust gasses that are exiting the chamber, encounter. Delta pressure deals more with the fact that the exhaust gasses exit in pulses or waves. And deals with the difference between.

When a person says they want to drop 1 7/8" primaries on a 305 and another chimes in and says "no, you need some back pressure" what they are really meaning is delta pressure. as you increase the primary diameter, you increase the distance between exhaust pulses. Keep in mind these exhaust pulses help the scavenging effect of an engine. So as you increase the distance between the pulses, you lower the engines ability to scavenge, or the action of one exhaust pulse heling to 'pull' the exhaust from the chamber that is next in the firing order.

As for cylinder heads, pop off the valve cover ad look at the casting number, it should be stamped between the rocker arms. Look up those casting numbers and then do a search and see just how useful the heads can be made. But yes, you are on the right track. Start with a full exhaust make-over (headers, high flow cat - if you so desire, good aftermarket catback such as Hooker's)

 

LG4= headers and y pipe, 3" catback, dual snorkel with KN, tuneup like plugs and wires and timing work, maybe a cam.

If you do these mods you will fix the flaws of the LG4 and have a nice running decent power increase over stock third gen.

 

Seems we 3 letter name guys tent to think alike.

Also need to add nothing wakes up a slow 5.0 like a good used $100-200 V6 3.42 axle.

 

I agree with this also - the exhaust and cam are the biggest bottlenecks.
An intake swap won't yield much of a power increase unless that air can get out freely.

 

alrighty, thats what i'll look for then. some heads of a better casting(after i check mine), some headers, and intake mani., a cam, and a exhaust.

the stock carb is fine for a while i guess, i i want to retain some gas milage ..

thanks guys.

 

You probably are already aware of this but I gotta state it, when the time comes to find a differen't set of heads, make sure you get heads that have the same size chambers, (usualy 58cc on 305's). A buddy of mine at work has a full sized 78 chevy pick up that has a 305 in it. He replaced the heads with a new set that he aquired for cheap and wondered why he lost power. Turns out they were open chamber 350 heads (76cc) that brought his compression down to 7 to one.

I too would agree with all the other guys.

A nice set of headers and a 3" cat back.

I got the "Pace Setter" from JCWhitney, which is a 3" mandrel bent system with 2.5" dual outs, for like $165.00. I sold the muffler on ebay for $60.00, then turned around and got a Flowmaster 80 series muffler. The system total cost was around $200.00 and is almost identical to the Flowmaster American thunder system.

I got my headman headers and "Y" pipe for $60.00 off a firebird that was in the bone yard, they look to be less than a year or so old.

I like the Wieand Action+ EGR intake. (its a Stealth with egr, just my prefference)

The CompCams 252H would be a good choice if you have an ECM, and that cam has a C.A.R.B. #. No ECM and I would use a 268H.

I like CompCams but its just a matter of prefference.

 

Ditto

 

I didnt know. Thanks for clearing it up.

 

well the car was an orgional V6 car, so it already has the 3.42's...non posi though

what do you guys think the car would run in the 1/4 roughly like it is now...160hp, and 3.42 gears??

and how much would some better flowing heads(complete with roller rockers and bigger valves), a alum. intake mani., a set of 1 5/8 headers, and some true dual 2.25 inch exhaust shave off that time?

maybe i could get a cam too....i would just like to break into the 15's....much trouble with that setup?

 

Replacement

 

not sure what ya mean by that?

 

I think he is referring to your original question:

 

o...good one..............

i would if i could. but i'm broke at the moment.

 

That motor looks awesome.

If it has been maintained as poorly as the exterior suggests, I would save my money for something else.

When the motor came out of the blazer, did it come out, sit in a pile of salty snow for 7 years, then get dumped in that car?

 

actually you would not believe how smooth it runs! there are no misses or uneasy rumblings in it...but it does rumble . there is not a puff of smoke when i start it up either...besides some white steam because of the coldness here.
the motor has ~50,000 miles on it.
its a great motor, and thats why i don't want to ditch it for another motor yet, i want to make what i can of it..

i am looking for a 5-speed for it too.

if i have a V6 5-speed tranny, is there any way i can just change the bellhousing to a v8 one and then put the 5-speed in there?