Ok so I am finally going to get to build my car after waiting for so long.. I now have in my possession AFR heads they are stamped Lt190, ported to 58mm intake manifold, crane cam 1.6 roller rockers the gold ones, true duals, and now I have to purchase a cam which I am calling Comp cams in the morning. Here is the questions that I have which lb injectors Do i need, is the stock size push rods the right length or do I have to change them, doing the top end is there any special gaskets that are needed with the new heads or do the oem work as far as the thickness and durability. I bought the heads used but they look brand new and I have to buy guide plates should I call afr and buy those or are all guide plates good. And lastly I am a dyi kind of dude but am I biting off more than I can chew doing this all myself minus the tuning. I don't have a lift or anything I am leaving the motor in the car is there any areas that are notorious for being tough. I have done a lot of reading but still nervous about doing it myself. Thanks guys in advance this forum is a life saver..

 

Call the boys and girls at AFR for a cam that complements those heads. I suspect they know the flow characteristics better than Comp does...

You will have to change the pushrods, if for no other reason than going to guide plates. The length will be different as well. You'll have to measure once everything is installed.

Injector size has to do with horsepower targets. After you decide on a cam and get a target for horsepower come back and we'll help with sizing. I think the calculation boils down to expected HP x 0.07= injector size but I could be mistaken. I used the formula every time..old school.

I used the GM head gaskets for the iron headed LT1 which has, I believe, a .028" compressed thickness vs the stock head gasket which is closer to twice that. That's worth a half point of compression...

Things to watch out for;

The steam pipe banjo bolts on the back of the heads are a pain and you often ruin the whole assembly trying to get it off. Buy a new steam pipe and seals to head off this problem.

Replace all the seals on the front cover while you have it off. Yes, sounds obvious.

You can replace the cam with the engine in the car but it is tight on space. The radiator comes out, obviously, and you can maneuver the AC condenser up enough to gain access. If the motor mounts are worn you might have to jack the engine up slightly to get a straight shot with the cam.

I'd replace the timing set....a bunch of guys think this isn't needed but I was going for a roller chain and an opti update at the same time. Check into this....

You'll have to lower the oil pan in front to reinstall the front cover. Don't even bother trying not to.....lol

Be careful of the water pump drive on reinstallation....the splined shaft can makea mess of the seal.

Replace the water pump.

Double and triple check the timing marks on the timing set. Lots of folks mess this up because they can't see the marks due to tight spaces.

Double, triple and quadruple check the opti spark when you install it. Yes, it's impossible to get it wrongs. Lots of guys have done the impossible!

You'll need a tune. An aftermarket guy can get you going and with common parts be pretty darn close. There are several guys used...do a search and read all about them...or you could do it yourself with a program you can buy called LT1edit.

That'll get you started.

 

Thanks man that is a great start I am trying to get it all installed in a long saturday is this going to be a long shot??? I am doing this work to my daily driver so I cant have the car out of service to long so I hope it doesnt take to terrible long. As far as push rods you are saying that I cant pre order them so I have them ready during my install??

 

That's right, you have to measure with everything in place to get the correct length. That's just how it is, unfortunately.
Your car won't be down long with overnight delivery....

 

Ok so I got a few more questions when setting preload on the rr I seen that some guys went a full turn and some went half a turn and also I am going to go with short travel lifters and some guys soaked them in oil while others said dont do this??? Just trying to do it right the first time..

 

Never heard of "short travel lifters." Which lifters, specifically, are you using? I like to err slightly loose, 1/4 TPZL with stock/replacement LS7s.

You can soak them in oil if you want but it isn't necessary. If they are new lifters just clean them up real well, dunk them in oil for a few seconds then throw them in.

 

I agree and actually think it's more important to clean them than to soak in oil. The same is true of the pushrods...you'd be amazed at the junk that comes out of those when they're new.

One other thing comes to mind. I'd recommend changing the rocker studs while you're in there. Some of the stockers I've seen don't have a particularly flat top which will make keeping the preload adjustment a little tougher. If you do change them, use a little teflon tape or sealer on them...on some ported heads the studs actually reach to the runners...

 

When I installed my roller rockers I had the same question. I ended up going with 3/4 turn because it was between the full turn & the half turn. also the manual said 3/4 turn...

 

I bought a XFI cam kit from Comp Cams & if you go to their website & check cam specs for your cam they list which pushrods & other parts to order with each cam kit...

 

You can not simply go to a website to tell you what pushrods to use when assembling a new top end. Things that effect pushrod length are:
Valve assemed height, head gasket thickness, head height (used heads could have been machined) and the list goes on. The idea of measuring is to put the entire 'stroke' of the rockers' action on the center of the valve.

It's possible to estimate with stock heads and gaskets and rockers but everything else should be measured.

 

Hey guys thanks for all the help I feel more sure I can do this install myself and you tube helped alot to. But I called the only place near me to get a price on a tune and its 1000 bucks is this to high or about right and he told me that the afr heads I have are not very good heads at all does this seem right to you guys. I have the afr 190cc thanks

 

$1000 for a tune is absolutely ridiculous. Pick up a mail-order tune from someone like Pcmforless.com. Runs around $150. Chances are extremely good that it will be WORLDS better than a shop who isn't familiar with LT1s.

 

Those the old 190cc AFR's for LT1's? Are they box stock and have not been ported? My friend ran those 190 heads on a sbc L98 with stealth ram intake and 280xfi cam. Had valve float... still made 330whp by 5700 rpm before the valves went bonkers, but that cam was on its way to peak by 6300-6400-ish rpm I'd estimate. Should have been 350-360 whp all said and done. Not bad but they would improve with some good port work to bring them up to modern AFR spec. You can get them flowing another 20-30cfm, they'd be capable of 400whp I'd think.

Not sure why they would say they are not good heads. Compared to newer AFR's they aint that great but they still can make ok power.