DarthIROC

Im sick of baing able to stomp people on the streets with the Torque that the TPI puts out but not baing able to back it up at the track because the stock TPI wont pull after like 4800 RPM. I would like to buy a super ram or somehting but I dont have the cash for that and just about every after market part for the TPI hits you for $300 and thats just one part.

Im getting what used to be a 750 Double Pumper off my uncles 11 sec '55 but it has been modified and now I think it has 78cc jets in the front and 72cc in the back and Ive pretty much decided on a Weiland Team G manifold. Some have told me that may be too much for a 305 but with my Block .040 over and the large cam I have in it I think I can make the big carb work.

Ive heard people talk on here about the FI HEI distibutor wont work right with a carb and you have to go to a non computer controlled HEI or something to that effect? What else would I have to get? All I can think now that I would have to have is a Carb, intake, Air Cleaner, and maybe distributor pending what you guys tell me

Zepher

Yes, you will need a new distributor. You won't get any timing advance if you use the one you have now.
You will probably need a new alternator bracket as well since the TPI one and the carb ones are different.

I went from carb to TPI, and now I am in the process of doing my LT4 swap.

baddest305

i did the switch from tpi to a carb set-up and had to change the distributor and and modify my alt.bracket. best move i've made!

AutoRoc

I used a Holley 600 Carb, Edelbrock Performer Intake, ProForm Vacum. Adv. Distributor, Mallory 4 port Fuel pressure regulator set at 9 PSI, custom made rubber fuel adapter lines. That's it really. Wiring the Distributor took a few cuts and solders but my buddy Joe is a wiz so he took care of that quick fast and in a hurry. Oh yeah, he wired the fuel pump to be on constantly and it's been working perfectly for a few months!!

What needs to be done to the ALt. bracket? We didn't do anything there.

FWIW, My car used to pull to 4800 RPM, now i shift at 5500 because the factory fuel cutoff is like 5600 from what I feel. The engine would be just right is I shifted 1-2 gear at 5800 i think...later fellas

87ROC

I did not have to alter my alternator bracket and it is very sturdy. You will definently have to control the fuel pressure. A carb does not like any more that about 7 psi. The three port mallory for around 90 bucks will handle that. I personally went with an inline carter pump that stays at 5 psi.

The connector that goes into your coil write now can be cut and used for the older style HEI distributor. The one that has voltage when the key is on is the bat wire and the other is the tach. I just crimped on connecters that are similiar to the ones that go on speakers on there and they fit on the Older style HEI fine.

Good luck with the mechanical carb. I assume since you are running a large cam you have either upped the converter or are running a standard trans. Cause is not you will probably kill your motor off the line. I don't mean broken but flooded out.

DarthIROC

So whats the difference in the Distributors? Why cant you just unplug the TPI one from the computer?

Zepher

The computer one controls the advance through the computer.
The non-computer one controls the advance through vacuum or if you went with a mechanical one, it is by rotation of the rotor.

ZZ

I don't understand why y'all crap out at 4800 with 305 tpi setups. I'm pulling hard with TPI right up to 6K where I have the fuel cut-off set. All I did was port the plenum near the throttle body(free), mild porting on the heads(free), and stuck in a mild LT1 cam($20.00), and bolted on headers and exhaust.

DarthIROC

By Mechanical one do you mean a non HEi or points distributor? And my unlce has the same distiutor as me in his 305 s-10 with a 750 cfm Edlebrock and he says he just didnt plug in the big computer plug. I havent ever driven it so I cant say if it runs perfectly but what would happen if I just unplugged the one I have.

Also correction on the jet size in the carb Im going with its 76cc in the front and 78cc in the back.

IROC5.7TPI

Well, I take it that the PROM I sold you didn't impress you much

IMO the Team G is waaayy overkill as is the 750 holley with bigger jets.

You need a dual plane intake and a 650 carb. Don't mess with the jets unless you know what you're doing, as you will more than likely screw something up (not that I'm calling you incompetent.... ).

I agree that a carbed setup will pull nto the higher RPMS and give you more at the track,but I wouldn't expect it to solve all of your problems. Look at Denny (Autoroc)... he says hes getting into fuel cutoff at high RPMS. I don't think its fuel cutoff due to the removal of the ECU, but he still has issues to resolve.

87ROC

If you unplug the computer you should not get any advance off idle at all. The only advance you will have is what is set at idle.

The typical HEI from the late 70s had both mechanical and vacuum advance on it. The mechanical is controlled by springs and vacuum by the canister on the side that plugs into a port on the carb that does not have vacuum till the throttle plates have been opened. The vacuum advance gives a little extra advance below 2000 rpm for a smooth transsision into the mechanical advance of the springs. You typicaly see 8 to 10 degrees advance at idle and full on 30 degrees or so at around 3000 rpm.

The old HEIs are cheap and easy to find in junk yards. It would be well worth your uncles time to give it a try. It is a very simple operation.

Just as a side note. A Q-jet is also very inexpensive and easy to find and can flow as much as 750 cfm but has a very good metering system so bog does not occur. Same goes with a 750 cfm holley with VACCUM secondaries instead of mechanical.

DarthIROC

Please dont take it that way at all I had actually decided to go Carburation while the Money Order was En route to you. And you can feel the difference.

Other than the fact that as I said Its was more expensive and complicated in my opinion to build the TPI than a simple carb set-up. Not the uncle that I mentioned with the 750 in his S-10 but another one who ussually helps me with my Z has been building mucle cars for 30 years and has had several 10 second cars that he built. He knows how FI works but he knows alot more about how to make Carbs go fast. So its just a matter of I have more resources in my corner on the carb side.

As for you saying the team G and big holey would be overkill I have a 650 cfm Edlebrock and a regular Weiland dual plane at my disposal too. If i decide one isnt working out Ill switch the set-up and critique which goes better.

IrocSS85

glad to hear you have a dual plane intake and smaller carb. to try . that intake is no good on the street. Id sugg. either a torqer II or the edelbrock rpm intake. the 750 is too much and the mech. sec.s. will prolly bog cause it cant use that much gas that quick. but it CAN work, just not as good as the RIGHT setup.
I have mechanical sec.s on my Iroc but I also have 3:73 gears, stall conv., full length headers and dual exh, more compr., and on and on. If I had a basic 305, Id go w/600 holley vac.sec..s, edelbrock rpm intake, 3:42 gears(your 355 gears are great too), sat. night special stall conv., and HEI distr.. and def. dont put a bigger cam in there. thats already a pretty big cam for what you have.
did you port the heads at all? what year car did those heads come off? whats your comp. approx. now? do you have a stall conv.?

good luck
chris

DarthIROC

Actually I hevent bought the intake yet I could still Change my mind on that. I have the old Weiland Dual plane but I want a new one. Ill look into the Edlebrock RPMs (just got my Christmas bible.... I mean Summit Issue today) The only thing I have right now are the old intake and the bad *** built Holley.

Im not sure what the heads are off of. The guy at the machine shop told me they were casting #186 heads which from what I can find actually came off of the chevy 302's but there not 2.02 valves and I think that thats all the 302's came with. I put my valves up to a set of what I know to be 1.94's and they were a hair bigger so I think that the valves are 1.98's. I havent ported the heads myself but the guy I got it from had done some machining to it, so he may have them ported. Since Ive had it I got them shaved I believe 40 thousenths, hot tanked, and got a 3-angle valve job.

I think the compressions a little shy of 12:1. I had to turn the crank by hand when we adjusted the valves and it wasnt easy

And to clarify something I actually have a limited slip 3.73 on there now. I have the posi 3.55 and I put it in my signiture because I thought I would get it under the car long ago. But things happen; you know how that goes.

You say that the set-up I had will work but wont be as fast as what it could be. How much of a difference do you thing it would make If I went with one of the intakes that you listed? Becasue Ive pretty much decided Im at least gonna try the big gnarley Holley.

sorry about the long post but I wanted to answer all you questions to the best of my knowledge

IrocSS85

an intake mann. can make a huge diff. I had a holley strip dominator on my big block along time ago and it was going 13.5's at that time. after an intake change to the rpm, I picked up .3 just from that swap alone. and it had alot more low end torque on the street.
I dont think you have that much compr. cause it would take dome pistons to do it w/your 350 heads. 305 heads have 55cc chambers and the heads you have either started w/64 or maybe even 76cc chambers. w/that much compression youd be on race gas or use an additive to keep it from spark knocking.

Id keep in the 3:73 then to try that first. w/that big ofa cam in there you may need it to keep you out of low rpms.

Im not an expert on making power w/a 305, but Id think youd be making around 300-340. anybody else got a guess?
mid to low 14's is what Id expect.

and the carb will work if you can tweak it enough. like change the power valve to match, the jets, stuff like that.