I have a 86 305 Z28, car was originally a tpi until I converted it to a carb due to multiple problems. I recently pulled engine to rebuild it and want to give it more hp with keeping the stock 416 heads. The engine has flat top pistons, edelbrock intake, 650 cfm 4 barrel Holley carb, hooker headers, and is bored .30 over. I'm wondering if someone could help me out with choosing the best cam for this engine using these heads. I will be using the car on weekends and taking to small street races would like around 300hp. Plan on building up tranny(700r4) and rear end next... I was looking at the summit cam K1102 but would like suggestions, please help thank you.

 

Welcome to TGO!

I have this:

Lunati 20070721

This one won't work however due to the valve lift requirements which would require you to have some good head-work done.


However, running factory heads will be a limitation. If I were you, I'd seriously look at getting a set of aftermarket heads or porting yours and upgrading to 1.94 intake valves. This will wake up the motor since the heads and exhaust were MAJOR choke points in these cars.

However, if you know the specs of your motor since you're having it rebuilt (Decked, line honed etc?)

I'd honestly call Lunati or Comp Cams and tell them "I havet his motor" and let them walk you through a cam selection for it.

Then, get a 3" catback exhaust and some Hooker 2055's or Dyno Don headers.

This may also be of some help:

Hotrod Magazine 305 build 325hp

 

Thank you for the information and i do apologize not that it makes to much of a difference but engine is bored .040 over. I'll give comp cams a call like you have mentioned. I don't know any other information on the motor unfortunately. I think I'll keep the 416 heads and do some port work to them and change out springs accordingly to the cam I buy. I also do have a 3" cat back exhaust already.

 

Do you plan on doing all the work yourself or have a shop do it?

 

I plan in doing everything myself except machining and port/polishing have a machine shop nearby that I use... I plan to rebuild 700r4 tranny after engine is done and install and probably like 3000 stall converter or so and swapping in a new rear end with probably 3.73... Just want the car to have some more power I only plan to take it on weekends, shows, small street races... I've read on a previous forum that the comp cam XE 268 may work pretty we'll with my setup if I change out the valve springs, studs and rocker arms... Just don't want to have a bad setup in the end after all this work.

 

Which is why you want to call the cam makers and have them let you know what they think would work best for your combo. Now, each of them will say "I think ours is the best". They'll paid to say that. But they generally won't steer you wrong for a cam choice. I would have the block/pistons mic'd though to find out what the deck height is of your block and how much your pistons affect the CC of the heads. It will all affect your compression ratio.

You won't need a 3000 stall in a 305 unless you run a cam that has a 3000rpm+cam. you want to be about 400-500rpm above the bottom of the power band. so if you cam says 1600-5000rpm, you want a 2100-2200 stall.

I have a 2700 stall in my car with a 1800-5600rpm cam. It's a little bigger than it perhaps should be.

 

Very helpful info I appreciate it. I will give comp cams a call tomorrow morning and try to get more info on this motor ASAP I'll let you guys know what I find out. Thank you again...

 

If you plan on rebuilding the tranny, call Dana at Pro-Built Automatics for your rebuild kit. One of the best guys in the business. He'll even rebuild it if you want him to, you will have to pay shipping though.

 

The 1102 cam will not give you 300 HP on your 305 but would be a good mild cam for a stock rebuild. The 1103 cam would be a better choice but again I don't know if it would give you 300 HP. A even better cam in my opinion if your wanting to run a summit cam would be there street strip cams as they have a tighter LSA SUM-1788 would be a good cam. It will not spin too high for your heads and will sound nice. I would use something like the TCI Break away torque converter. It will probably not stall as high as advertised being its a 305 and the 3.73 gears you want to run and would be a great match to the SUM-1788 cam. If your carb is a double pumper you might try a vacuum sec carb if you can to see if it works better for ya. I don't like double pumpers unless I am running a huge stall. Also stay away from a high RPM duel plane unless your running a big cam. A duel plane intake with a idle to 5,500 RPM power band will be just fine for your 305.

 

If your going to get screw in studs pull the old ones your self it will save you about $100. If your going to have work done to the heads and have the cash you might be better off getting new heads. To have screw in studs and have my valve guide bosses machined cost me $580 That was pulling the old studs, installing new screw in studs, machine valve guide bosses, dis assembly of heads, re assembly of heads, checking valve spring install height and re surface my heads. This was to a set of new heads and did not include the cost of the springs, retainers and locks. You don't want to dump too much in to this motor or your going to look back and kick your self for not just buying a 350.

 

I would avoid TCI and B&M like the plague. Do a search here on the boards here and you'll find that about 70%of the time, the person who bought it is unhappy because it either broke, is too loose, or doesn't stall correctly. You want Edge, Circle-D, or Vigilante. Yes, they're twice as expensive, but this is not an area you can skimp on.

 

Ya that's true I have known several people that have blown up B&Ms but it was all the torque masters the holeshots are ok. I did not know TCI had problems too. I am going to use a PATC Super street raptor 2 for my next converter. There $400 and have an anti balloon plate for use with NOS. They claim there good to 550 HP. There converter with out the anti balloon plate is only $300 but I feel NOS or not the plate reinforces the converter and makes it stronger and more efficient by not letting it flex as much and I might spray my motor some day.

 

I went with the Vigilante myself, nearly $850 but I've never heard a bad word about them and didn't want to go sub-part with such an important part.

 

I called company cams this morning and they said they recommend the XE262 but if I really want to push it the max with my setup would be XE268 but they said I would new there whole kit with timing set retainers springs etc... They also recomended a 2000 stall(never asked a recomended brand) I am listening to your recendations as I definitely want to do tho right and only once. I want a mild build but don't mind spending extra to get parts that will last...