onebadtwo

I am swapping a LS1 from a 98 Z28 into a 64 Nova. The LS has 118,000 on it and ran before it was pulled with no weird issues. The LS will be backed with a T56 also from a F body. I have access to a set of used 799 heads (W/ 90,000) for a pretty decent deal. I guess my question is, how much difference is there between the 799 head and whatever is on my 98? I had planned on finding an LQ4 later after the car is finished to build and drop in. Would the head and cam swap be a good idea for the year or so I plan on running the LS1?

Ethan[ws6]

iTrader: (13)

799 heads are the same as 243 (ls6/2) heads. They are the best flowing FACTORY cathedral port heads. They will be better than the stock ls1 heads by a bit. If you can get them cheap and you are planning to do a cam anyway, buy them and throw them on.

Sales4@Texas-Speed

iTrader: (4)

I agree, those will provide a notable gain compared to the 98 heads. Finding a small cam paired with those heads will yield a notable power gain with no drivability changes.

wildcamaro

iTrader: (15)

98 heads are the least desirable of all ls1 heads...I saw a good boost in power running the 243 heads which for all intensive purposes are the same as 799 heads...it's worth doing... Although do your self a favor and hook up a cam while your in there though!

garygnu

check them for valve seat leak ,and get a valve job if needed.

thunderstruck507

iTrader: (18)

Definitely a worthwhile upgrade, especially if you can get them milled a little. Then pair them with a cam that makes peak HP low enough you can shift under 6500rpm (to save the 98 rod bolts) and you should end up with a stout but reliable combo.

Ws6kid.

I agree. find a cheap set and mount them on with a cam swap.

onebadtwo

OK... What cam should I go with? I don't want it to be very rowdy, a mild but noticeable idle is what I would like to have. I like the idea of keeping it below 6500 due to the rod bolts as well!

thunderstruck507

iTrader: (18)

a 228R on a tight lsa for off the shelf, or call Texas Speed or EPS and let them help spec you something

wildcamaro

iTrader: (15)

I run a comp xer273 224/230 .580 114 cam and if you ask me it is perfect for the ls6 heads and intake setup because there is no sense getting a 600 lift or higher cam since 243/799 heads won't flow great when stock from there...I also have a 98 z28 and I dropped a second off my time by going with that cam and ls6 heads and only a mail order tune...your car already has the 28.5 lb injectors which is good, although I'm not sure if mine are maxed out due to mail order tune and I haven't used a good scan tool...you will be happy once you do the heads/cam the first time it pulls up to 6500+ rpm!!!

onebadtwo

That sounds great. How much power should a setup like this make with an LS6 intake, longtubes, and a mail order tune? Will the regular beehive springs work with a 228R?

Sales4@Texas-Speed

iTrader: (4)

You will want to look at either a PAC1218 or a comp 918 for the springs. With a manual transmission we would be looking for this package to make anywhere between 400-420rwhp.

baxsom

iTrader: (6)

Does the 98 require new valve covers and coil brackets for the 799 heads?

Ethan[ws6]

iTrader: (13)

Do not get the 918s lol. I hear more horror stories than anything from those springs, myself included. I had 7k miles on mine with the torquer v2 and one of the springs randomly broke. Dropped the valve and have to replace at least a piston, sleeve, and head.

JustAFooL

iTrader: (45)

I'm also curious about if valve covers and coil brackets have to be changed with these heads

Sales4@Texas-Speed

iTrader: (4)

Yes the valve covers and coil pack brackets needs to be changed if you have 98 heads. 98s came with perimeter bolt valve covers and the 243/799s are all center bolt.

JustAFooL

iTrader: (45)

Where can you buy these at??

JoshuaGrooms83

iTrader: (2)

been thinking about doing the same thing latly. still cant decide what i wnat to do yet, but 243/799 head for sure are going to be on my 98 TA was well.

01ssreda4

iTrader: (96)

Biggest advantage for the 799s is the newer style valve covers. Other then that you won't see any gain from switching. I've run my car back to back with a 799 vs a 241 (stock) head and a 241 milled 025 and the 025 milled head "felt" the strongest of the 3. 799s are not as good as the famed 243s, mostly because the casting is rougher and it does not flow as well, though lots of internet experts will tell you different. It is a great platform for P+P work. Food for thought.

thunderstruck507

iTrader: (18)

Wouldn't the 241 milled .025" be a decent bit more of a compression bump over the slightly smaller chamber of the 799? If so I do not doubt they felt stronger at all, especially off idle and through the midrange. From my experience, compression and gears are the 2 easiest ways to make the butt dyno happy.

I did not run my 799s stock but once they got a light work over and milled .010" they made it like a whole new car down low. I would bet money a 799 with a good mill would be great for the butt dyno. The gains up top would be harder to notice with a stock set since you are talking about under 15rwhp which is not enough to feel on a 360-400rwhp car IMO.

Comparing the 799 to a 243 is much like comparing an 853 to a 241. You will lose some flow due to the rough casting but most people who have messed with both enough will say the effect will be small.

Either way, the 799s give you more room to grow since I don't think anyone would argue for the average ported 241 versus the average ported 799.