Merry Christmas all. Ive been on this forum a few times, once as an owner of a 98 Camaro RS a couple years ago.

When i got rid of the car, ive had a few others in between leading up to my first 96 Impala SS, and now my number 2 Impala SS. Ive done some mods to my black SS, which has been totaled earlier in the year, and everything that i was able to salvage has been carried over in to number 2.

That being my built pcm, 1.6 roller rockers for the stock iron heads, CAI, and exhaust.

Doing well with my modding thus far and ready to continue into the new year. Ive found a LT1 with aluminum heads at the junkyard on a 95 Trans AM. I hate to let those heads get away from me, so i grabbed them. $80 bucks. Going to get them reconditioned and ready for a swap onto the SS here soon.

I was told that the aluminum heads take a different set of roller rockers versus the iron heads. Research shows the irons use rr's to fit 3/8 while the aluminums use rr's for 7/16. Is this true and if so, does someone have a part number to reference for shopping or do i just ask for 1.6 rrs for an 93-97 f body lt1?

Also, ive read that the aluminum heads use a different head gasket than the irons to help beef up compression. If it is not much to ask, what part number for the head gasket, or just ask in the same manner for the roller rockers? Thank you so much...

 

if you can afford it have lloyd elliott do the heads and your intade. you can get 3/8 studs if thats what you wish, mine had 3/8s stock and i switched to 7/16. im using very thin head gaskets to bring compression up a tad. i think there iron head gaskets.
i copied this from my garage list

ARP 134-7103 7/16 rocker studs
Trick Flow TFS-21407100 Pushrods, 5/16 x 7.100
comp cam 1305 roller rockers 1.6 7/16 pro magnum
tpis performance roller lifters
GM performance composition head gaskets
part # 12553160 .028 compressed thickness

 

Thanks, that give me some ground to move forward. Now my next question is, between the 2, is the f/y body cam more aggressive than the b/d body or visa versa? I hate to keep asking the seemingly elementary questions, but with juggling with between studying the f/y body lt1 and the b/d lt1s, every bit of help would be much appreciated.

 

f body cam is a tad more aggressive but has a tad less torque mostly at low rpms. lt1 likes high compression, have the heads ever been shaved, if not you may wish to up the compression a tad by taking a .015 layer off.

 

The heads have not been shaved.They still sitting in plastic from the JY visit a couple weeks ago. So .015 off the heads, as for the f body cam ehh, im still researching a great deal on cams. Will likely pass on the cam for now, because i dont want to run into serious problems with tuning and so on from a cam swap. If that makes sense. LOL

I will be doing a 396 build later on, so i will save that battle for then. For now, im just looking to beef up the SS a bit without getting too in depth with it, cause i have other plans a projects outside the hood that is. LOL. If i can get to around 375-400 crank horsepower, i will be cool til the 396 deal comes. Only guessing, but with the 1.6 rr's, cai, 2.5 catback, and current tune, 2100 stall converter, plus done all my maintenance, im probably close to 325-330 now. I think... I hope? LOL.

 

I don't think you're near the 325 range with just those mods. Even though GM usually lies a little with their numbers, the B/D bodies were rated at 260 FWHP. I would put you at maybe the 280 range, maybe higher if the tune is good.

I am curious on two things though.

1) Did you get the computer harness from the T/A as well? And what year Impala?

2) Why 396 and not a 383? Reason I ask that is while 396's are cool, I never felt that the 13 additional cubic inches, as well as extra clearancing, money and machine work was worth it over a more common 383.

 

I havent had it dynoed, but it sure drives really well for it to be under 300 horsepower. Lol... as for the harness i did not. Why do you ask? In sure that T/A is on borrowed time at the yard. Is there something else i need off there? My SS is a 96. As for the 396, not sure why i really want a 396. I would say its to be different from all the 383 that everybody else has, i will admit its been tempting and probably easier to just do a 383 setup. So pending research, and parts availability, only time will tell which i end up with.

 

It drives well cause you're engine was originally set up for lots of torque to get the boat moving fast. Haha. But a set of headers will help it breath better.


Reason why I was asking about the harness is if it was a matched year to your Impala, why not swap that in if you swapped cams so you wouldn't have to worry about the tune. But since yours is 96 and that was 95, it would have been more work than needed.

Not saying the 396 is bad route or any thing cause it'd be really cool to see someone do one on here for the LT1 since I don't think I've seen any one do it yet here, just a lot more work and usually money for 13 more cubes. Either way, they're both torque monsters and will get the weight of the SS moving quick.

 

Well after watching my kids rip open their presents, i figure id use some down time to research some. So other than the āluminum head factor, were the specs still the same as the irons at 1.94-1.50? (Tuning question). Im asking cause im doing a street tune after the head swap. And whatever is different outside the weight loss of the heads, i want to document so i can give the tuner accurate info. I would do another mail order tune, but i think i will be better satisfied when i see what the tuner is doing live. Plus he is doing other work on the car too.

Back to the studs, i forgot to mention my rr's are self aligning. I dont see much of anything self aligning for the 643 heads. Just everything with guide plates or 1.52 sa. Unless im not understanding something, can i remove my 3/8 studs from my iron heads and install them on the aluminums? Or are the aluminums already 3/8 and people just do the 7/16 as an upgrade? Thanks

 

stock iron heads flow a tad better than stock aluminum. aluminum will port better and imo run cooler alowing for higher compression. iron heads have the studs pressed in, aluminum are screw in. self aligning will work i just dont know if they will clear the valve covers.