i have a 74 camaro that we just got out of storage, been there since 96...anyways we my father and i are slowing goin throught it. My dad cant remember what gears are in the rear end but there way to tall....i can do 50mph in 1st year, goin on the freeway and in 4th what you step on it, its bogs and goes no were pull her back into 3rd its a lil better, now drop her into 2nt and bingo theres the power band. The motor is a 300hp 327 from a 64 impalla ss.....the heads are from the stock 74 350 motor, and the cam was put in over 20 years ago its a special order cam that you could have put in the 69z28s from what my dad tells me.....all i know is it has a good lobe to it at idle. it also has a edalbrock torquer manifold and a holley 650DPer.....with that said what are my best options for gears...3.73s 4.10s would 4.56sbe so short?

 

If the cam is the Chevy "off road" cam that was a popular to swap for the 30-30 cam in 302s, it is huge. Add the lower compression from the 74 heads, and you need all the gear you can get with an M21. 4.10s minimum, 4.56 would be better. Unless you are going to drive it on the freeway a lot. If so, 3.73s, but I'd be looking to get rid of the heads in favor of some with 64cc chambers. A modern cam with a lot less duration and overlap would make just as much HP as the outdated cam in there now and have much more low end torque.
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Definately toss a new cam in it such as an edelbrock performer RPM kit. It runs REALLY hard is really a nice cam on the street. As far as gears, if you are going to just play on the street, go with 3.73s. If you are going to race it only go with 4.56s, but street strip go with 4.10s. We have 4.10s in our vega with a 327. It goes through the lights at 6300 rpm with a 26" tire at around 111mph... 327s need good gears to get them outta the hole or else 350s will stomp you in the low end. With your car you can run a bit taller of a tire so I would go with 4.10s. That thing will haul butt.... Good luck!!

 

edelbrock performer RPM cam sucks compared to todays technology, lazy ramps and too much duration for lift given. Call comp with compression, rear gear, trans, engine size, etc etc and they'll choose one based off your combo.

 

Thats funny considering my performer RPM out ran my comp that they chose for me. Only reason I changed edelbrock is because I broke a rocker stud on the exhaust and it shot the pushrod through the lifter into the cam. But again, Im sure a newer tech cam will be better but for the price its hard to beat. If you have the money go with a roller setup as well..

 

what is the chamber cc size of the 74 350 heads? the car will only be out and driving in the summer from time to time, but i would like to get it out to the track a time or two so im thinkin the 4.10s might be the way to go. we have also been talkin about doin an electric fan setup and pullin the belt fan, it has dual 2.5" pipes and cali turbo muffs on it that are lookin old, so im tryin to talk him into 3" pipe and dual magnaflows...with an X or H pipe in there, what do you guys think about that....is 3" to much? right now its also runnin the stock 350 filter setup on top and a paper filter.....we need to get a full k&n setup with the x-stream air cleaner lid, im thinkin with 4.10s, re-built exhaust, k&n setup and pullin the belt fan we should see a hole new car in the way she runs. what do you think? also what do you guys think about electric ign. over the old points dist. setup it has now?

 

74 heads = 76 cc chambers. Really knocks your compression down, that and the big cam hurts torque, especially with the shorter stroke of the 327. If you want to see exactly what heads you have, look up the casting # on mortec.com.

 

I would NOT go with a 3" exhaust, especially on a 327. Definately go with the 2.5" with an x-pipe and some better mufflers. A 2.5" will be good enough if you switch motors prolly all the way up into a mild big block so its well worth the money. Also, if you can afford it switch your distributor and ignition over to a MSD pro billet/MSD 6AL Combo, with MSD coil as well, you wont believe how much the car picks up due to that. Mallory also makes some good setups for quite a bit cheaper than MSD as well... The fan on my GFs vega was worth a tenth and a half in the 1/4, and a tenth on my 68 camaro... thats about 10-15hp.... As for the air cleaner, i have run a crappy fram paper filter and a K&N back to back and the K&N picked up about 1/2 a tenth in the quarter, so it is worth the money as well, plus it looks a LOT cooler. What kind of headers are you running? Full length? Mid Length? What about tube diameter?

 

76cc man thats a lot bigger then i was thinkin....the headers are full lenght the diameter im not forsure about but i took a meserment and there 1-3/8 or 1-1/2 there not 1-5/8, it would be nice to get a coated or stainless set....but there other things like gears well do first...baby steps. for an electric fan what are you runnin Green95Z28? seems like a 16-18" single fan will fit in side the fan shroud nicely. dual 2.5" with and x-h pipe got it!! ill look into the electric ign setup more also.....thanks for all your help so far guys. also what size is the 10 bolt in the rear...the rear is a 76 posi/locker rear end. 8.5" 10bolt?

 

76 = 8.5". Find out what gears are in there now. If you have taller than 2.73, a performance gear like 3.73 won't fit on it without a spacer ring (not recommended). 2.41 or 2.56 = you'll need a "3 series" posi carrier. 2.73 up = you can reuse the posi you have.

IMO, I don't think you'll get a lot of bang for your buck swapping for a better ignition on your application, unless yours is dogged out. High compression, high rpm engine, maybe, nitrous for sure. An MSD guy (MSD is in El Paso) saw my car at the track once, told me if I replaced my stock points system with their stuff, I'd get a couple of tenths. I thanked him for the advise, but passed on it. I've read tests where they pit points vs MSD6 vs hi perf HEI, little or no difference on the dyno. I did put HD points in my distributor so they wouldn't bounce at high rpm, and recurved it. If you do have a huge cam in there, much more return on investment if you replace it with a cam having 218 - 224 duration @ .050.

 

On the ignition side of things I did notice a 3 tenths of a second gain on my car VS the HEI setup, due to the WAY better timing curve in the MSD, yea a dyno will be close but it doesnt show the acceleration of the car (actually it kinda does, but whatever )... If you work at it, an HEI (in my opinion) can be made to be quite adequate for a lot less money for a street application, so angel 71rs has a good point, bang for buck... I needed the 6al for the 2 step rev control. The way I picked my fan was that i measured exactly how much room I had then I went on summitracing.com and picked the highest CFM rating that I could get for the room I had. Which (at the time) was the Flex-a-light black magic. Again for bang for the buck you can find some pretty decent fans off of stock late model vehicles out at junk yards that work great. Also, on summitracing.com you can get a set of 1 5/8 headers for 78.95, the part number is SUM-G9001. They might not be the best looking or whatever but they do get the job done on a tight budget. Honestly, since the exhaust is the most noticeable part of the car I would get that done first. The fans and stuff are good, but if the one you have works there is no need to get that right away.

Anyways hope this helps!

 

would a good coice of heads be the "double hump" heads that came on the older 302 blocks....and would they be fine with todays gas? we looked up the cam and the specs are lift.485 ....mech.dur. .346 on 1.5rr....part#3849346 casting#38493347.or would there be a better head that would fit the motor....we dont have the time/money right now to swap in a new cam and make the motor a "hyd. roller" i dont know much about the mech. cams....is there a big diff vs the hyd roller setup? i have a built 91 TPI motor with a 212-218 .487.496 comp cam in my truck... how much smaller/bigger is the mech cam i listed above?

 

the double hump heads are halfway decent stock replacements but nothing like today's aftermarket heads.. If they are completely stock you might have to put the hardened seats in.. IMO your cam and stock heads are fine for what you have, prolly not worth the money/time to change it all. Start with the bolt ons, once you've got those done then start worrying about the internals. IMO Hydraulic rollers are good for daily drivers, they make good power, are very quiet, but can be very expensive. For the cost of just the lifters you can get a flat tappet cam with lifters and valve springs to match. So it really depends on what you feel you have the money for... If your engine starts up and runs good, no need to tear it down until you've done all the bolt ons and save up your money to do the heads/ and cam at the same time, that way everything matches. You can tell the cam company all that is done to the car and they can match the cam to all the bolt ons and such you've previously completed. If you don't they would have to make one that matches to what you have now, or try and shoot for what you might do, which is not nearly as good.

 

alright ive got another question....what kind of timming should we put in this motor....when i got it out of storage it was runnin 4deg. its now at 8deg BTDC paople say we could probly go to 10-12 what do you think we should run it at?

 

10 degrees is a good base line to start at, keep bumping it higher(a few degrees at a time) till you get spark knock, then back it off, should be the sweet spot