I have a 98 Z28, I have ASP underdrive pulley, ls6 intake, 3:73 gears, TCI3500 stall,custom GMMG, AFR205 heads. I was planning to get a F13 cam but i am not sure if i should for a +2 or a +4 for the lsa. Will it be more difficult to tune? Which one would work better? thanks for your help guys

 

Futral's standard grind comes w/4* of advance. That's what I have in mine, on a 114LSA. Similar mods to what you have (stock heads), put down 391/357 locked.

 

I forgot to mention that that +4 or +2 will be on a 112 LSA

 

i would do a 114+4 or a 112+2 with that automatic

 

I dont think going either way is going to make a huge, SOTP difference. If you order it on a +2 I bet you'll have to wait a tad longer to get it, but who knows.

 

I do have an A4, I ordered the F13 cam 112+2, 3 weeks ago but there was a mix up so they said I could get 112+4 now or wait a few days for the 112+2.

 

what would be the differences between the 112+4 to the 112+2?

 

intake center line deg.

 

The +2 will shift the powerband 100>200 rpm upward.

 

So I would be better off to wait for the 112+2

 

Well are the heads milled??, in some instances less advance will increase PTV clearance.
But if your question only about performance, then no, no need to wait and a +4 should work a little better with your 3500 stall.
The reason is that if your powerband comes on sooner, then it ends sooner, keeping your shift points/power range within the stall shift extensions.
Also get the right head gaskets to give you a .035>.038 quench range.
To do that you'll have to measure your piston to deck distance +/- (in or out of hole).
(PTDD - gasket thickness compressed= Quench)
The AFR's have a double quench area vs a single on GM castings, so improving flame travel and speed by getting a nice tight quench is very benifitial.
Try to shoot for as close to 11.0:1 SCR with a .035 quench and that will be worth a few extra ponies.

 

Call FMS and ask for Alan he can give you the best advice

 

the heads are not going to be milled

 

Then get the cometic .045 head gaskets and assuming you have a stock block ~(.007) out of hole that will give you a nice .038 quench.
Personally, I would mill those ~.015'>.020'

That would bump your CR a little and increase your output.

 

Already ordered GM head gaskets, part#12498543, i think .035 or .038. Will it be more difficult to tune with the 112+4.