I have searched a bit on the board, and can’t seem to find an answer to my questions. I am looking into swapping a 327 into my 85 IROCZ and I am looking for specifics on the 327 vs. the 305. What I am looking for is information that will entail

What I will have to do to make an engine block that was never intended to be fuel injection work on TPI?

What mounting do I have to change to have the 327 fit in my bay, mate to a 700r4, and fit under a stock hood?

Has the head bolt patter ever changed on the SBC?

What aftermarket heads will fit on the 327?

What is the camel hump in the head referring to?

The EFI intake manifold interior bolts are slanted or straight? If intake bolt holes are straight on the head, all I have to do is modify the bolt hole on the intake manifold fit straight down and add a inclined clip to make the mounting surface for the bolt head to set flat across the intake, or the other way around depending on the circumstance, correct? My question referring to making a carb block work in conjunction with an EFI block is pertaining to the fuel pump block off plate, all I have to is add the fuel pump block off plate and a can run what ever cam I want?

Thank you for the help!!:rockon:

 

1. Install your fuel injection on it.

2.Nothing. Install it. Your flex plate, balancer, and accessories will all bolt right up. The one thing that won't is your oil dip stick. Your manifolds are utterly incompatible with the early block location of that. You'll just have to put headers on it.

3. No.

4. Any and all.

5. See pic. "Camel hump" refers to the casting mark you see on those heads.

6. The bolt holes on your intake are the same as the ones on early heads.

If the heads on this 327 don't have the accessory bolt holes that you see in the pic on the ends of the heads, then do not bother attempting to put those heads into your car; you'll never be able to get it to work. You cannot drill and tap them because the metal to drill and tap is not there. In all the years (about 35 now) since accessory systems requiring the bolt holes came out, I have yet to see even one installation where that style of accessories have been made to fit successfully on the older heads.

 

The 327 has a 4" bore with a 3.25" stroke while your 305 has 3.48 stroke like a 350 and I believe a 3.78" bore...anyway it's much smaller and limits the size of valve you can run. Besides limiting the size of the valve, the small bore shrouds the valve, limiting the air flow. Theoritically the bigger stroke of the 305 would boost torque production but I have never seen it when compared to a 327. The 327 is not excessively larger than a 305, I bet you could get by with just an adjustable fuel regulator to feed the extra cubes.

The 327 will except any aftermarket head with 2.02 intake valves. Pick up a set specifically made for a TPI motor and you won't have to worry about the mounting angle or accessory holes. AFR, Trick Flow (G1 and G2) and Edelbrock (Performer) all make replacement heads for the L98....you could also go to the aluminum L98 head, if your budjet is limited. I've seen them go on Ebay for reasonable prices. Just make sure you use a 62cc or 64cc chamber. You don't want to run pop-up pistons.

 

Seriously, Thanks for the help and answering the whole post!

I have a 100 wet shot of NOS on the 305 right now and currently saving the money to buy a Pro-Built. When I build the 327, I want it set up for high revs, boost and or N2O. I was thinking of running a forged dished piston with a set of Al Pro Lighting heads, but that’s all later down the road.

Are there any 327 I should go looking for (by casting #) other then the lrg journal block?

Are the 327 2 bolt/ 4 bolt or my choice? In the June 2003 issue of Super Chevy they did a Tech article on Milodon’s four-bolt main conversion. NOT starting a debate over, “is 2 bolt better then 4 bolt”, but is the amount of money spent on installing these rather beefy mains really worth the price you will pay.

Are there any problems that I should expect, i.e., not fitting between the finders, not enough hood clearance, 327 attracting meteors from outer space……?

RB83L69, you have stated that my 85 305 stock manifolds will not fit on the older 327, correct? I will be using aftermarket heads of some sort, so the Stainless Steel shorty headers from SLP shouldn’t have a problem matting to the block, or did I completely miss your point on #2? And a flexible dipstick should take care of the other problem.

Wesilva, just to make sure absolutely sure! I don’t plan on machining my block to work as a 327 but purchasing a 327 block.

 

Your stock manifolds will absolutely not work on the older block and allow for the existence of a dipstick. As long as you don't care about the dipstick, or if you get the right oil pan to allow for a dipstick that goes into the pan instead of into the block, they will work fine. A flexible dipstick will not help, unless you know of one that can come up out of the block about an inch, make a 90° for about 1½", then another 90° to point straight up again. However the SLP headers solve the problem completely.

A 327 block will accept any heads that a 350 block will, because it's the same 4" bore as a 350. Of course, if you get some kind of aftermarket heads, then all you have to do as far as accessories and intake bolt-up is make sure the heads you pick match the other stuff. The block doesn't care about any of that or vice-versa.

You don't "machine" a block to be a 327 block, you take a 350 block and downgrade the crank to a shorter stroke one; or you use an early small-journal 327 block and use the old inferior small-journal rods with the smaller bolts. If you're going to make a LJ one, you don't need a special "327" block; any 350 block will do, as long as you can get the downgrade crank to fit it (which might limit you to 2-piece rear-main-seal blocks, I don't know, I quit building 327s when I started being able to get 350s). The factory used the same block castings for 302, 327, and 350 simultaneously in 69.

As far as the 4-bolt conversion being "worth it", that's a kind of personal question... it's like whether life insurance is "worth it" Nobody else can tell you how much you need, it's however much you feel comfortable with.

327 blocks (being the same casting as 350 blocks) will fit anywhere that a 305 or 350 will. But since the crank is less metal, it may allow for a greater neutrino flux from cosmic rays to penetrate the oil and windage tray.

 

I totally understood that you were not boring your 305. I was just pointing out the strong points of the 327 block. If you are going large journal, I would choose a four-bolt 350 block with the one piece seal (Post '86)with the two piece adapters. I have a set of these adapters cheap. This will allow you to run roller cam without the huge expense of converting a non-roller motor. This opens up a whole world of great hydraulic roller cams for you that you can match to your upgraded heads. The four-bolt block, I believe is specific to Corvettes from 87 through 91. (I think in 92 they introduced the LT-1 which is a different animal.)

If you are bent on 327 block, I would use a small journal 327. The smaller journals generate less friction and you can pick up some free horsepower. All 327 blocks are two bolt and the conversion to four-bolt by using aftermarket billet mains and splayed bolts are far superior to any factory four bolt blocks. You might think this direction if you are planning on buzzing the motor past 7500 rpm. The decision to upgrade the mains is definetely a decision made by how you much you intend to rev it!

 

I really like the 327 due to its’ short stroke compared to its’ bore, hurts top end V.E. but the crank in doing a better job of pushing the piston up the wall instead of being busy trying to drive it threw the cylinder wall. As far as the main caps go, won’t using the smaller journal engine limit the structural strength need to keep the deflection of the crank to a minimum at high load and upper revs? I am not worried about losing horses due to friction when structural integrity is compromised. I want to build an engine that is a structural beast, even if it means waiting over three paychecks to buy the proper parts, my 305 engine is quit slow but fine…for the moment. What cranks are available with a 3.25” stroke? What type of crank would best suit this kind of setup (high revs and N2O/boost), steel, forged, billet, ect?

RB83L69, the headers from SLP will solve the whole dipstick mess or do I still need an oil pan that allows for a dipstick to run threw it and bypass the block? What about raping the oil pan in Mylar to block cosmic rays, sunburst, and solar winds. That should stop all neutrino flux due to extraterrestrial forces, now it’s onto blocking the magnetic field, stray piñatas and broccoli.

Wesilva, you have suggested using a block that is already setup for a roller cam instead converting an older hydraulic cam block. Even though the conversion parts are quit costly, isn’t the overall construction and design far superior to the GM engineers design? The reason I ask is because I think I remember read a thread over the topic. I am interested in hearing what other suggestions you have for a high revving 327.

Thanks for the help you guys, I am getting one great engine combination nailed down! :rockon:

 

The rod/stroke ratio of the 327 does make it a good motor to rev and build good top end power. As far as the structural integrity of the small journal, it doesn't seem to bother circle track people who seek out small journal motors and wind the snot out of them. The reciprocating mass of the crank, rods and pistons coupled with the rpm you plan to use will ultimately be the deciding factors in choosing your block main configuration. Keep the reciprocating mass as low as you can achieve with your allowable budjet. I am building a similiar motor but using a 400 block with a 327 crank. The plan is the same as yours though...to build a strong base for which I may add a turbo or NOS later. I have had great luck finding light-weight parts at http://www.racersauction.com. This site has a strong circle track following, which is good for you because your seeking some of the same goals from your motors. I purchased light-weight rods and pistons using this site. I had a large journal steel crank already and decided to have the throws undercut to lighten it up without compromising the structural integrity. Racersauction regularly has light-weight billet cranks for large and small journal motors at 3.25" strokes but they are pricey, even used...something in the order of $900 to $2000 depending on the manufacturer. I directed you towards the factory roller block because the conversion-type hydraulic lifters tend to be heavy and will limit your "revability" because of this. Your best bet, again, if you can afford it, is to look into the Street Roller set-ups with solid rollers from Comp Cams,Crower or Crane. These are the ultimate cam set-ups for serious street use. Next step down, in my opinion, would be the factory roller block with an AFR Rev Kit. Check out http://www.hotrod.com. Go to Tech Articles/Engines and check out the feature "More Power for Any Engine". It details some of the above discussions and gives you more to think about.

 

I stand corrected. All L98 motors in Corvette as well as Camaro are 2 bolt main.

 

Well, i've sorta got a fix for your dipstick problem as RB83L69 states it:

I had exactly the same problem installing my 350, which was a '70s block with a dipstick in the same place as your 327 has. My uncle did the two 90* (approx.) bends and worked it around the manifold i had ('83 stock). I had to make my own dipstick, and to do it i used the handle of a normal SBC dipstick and put a peice of small steel cable onto it. I cut a groove in the dipstick handle about 3/16" long (i left about 1" of the wavy top part right under the handle to do this) and crimped it together with the cable in it to hold it tight, then welded the two cimped ends together. I then welded the end of the cable (handle end) to the handle so it would not come off, not matter what.

It works great for me, but to mark it you will have to do an oil change. I filled my engine with 4 quarts, let it sit for awhile to settle in the pan, then used that to mark the low spot, then put in the 5th and final quart, let it settle in the pan and marked the "full" line.

Hope this helps

 

The dipstick isnt that big of a deal. I rednecked mine for a few months until I came up with a set of headers. All I did was install the stock dipstick tube, which i pushed against the head as far as i could. I then put the exhaust manifold on and tightened it down. This squished the tube to the head, but there was still plenty of room for the dipstick to slide in/out. I had no trouble with the dipstick and no leaks. Only problem....dont try to check the oil when the motors hot!! At least not without a rag to grab the dipstick. With it in contact with the manifold it gets VERY hot!

Anyway, it worked till I got a set of headers.

 

Wesilva- I would like to dwell more on the topic of the smaller bearing journals to increase power, but first, thank you for the link to HotRod Magazine’s website. I completely forgot about being able to read the tech articles online. Does using smaller journals increase or decrease the life expectancy of the engine, and does the same school of thought apply to using thinner piston rings? I understand that circle track racers use this engine building trick to free up horsepower but if engine mileage will only permit 30,000 to 50,000 miles its no good to me. What vehicles came with SBC engine that had a 4.000" bore, 2-bolt main, small journal bearings, and previsions for a roller cam configuration?

And for the dipstick problem, thanks for the creative ideas but I think I will just resolve the issue with purchasing a set of headers.

 

I know a lot of people that have got over 100,000 miles on their street driven 327 small journal motors. Amazingly enough, I just put a 350 crate engine in a friends '64 3/4 ton pick up and the original motor was....you guessed it....a small journal 327 with 150,000 miles of hard use. There are probably as many steel 327 cranks as there are cast ones out there. If you can keep your reciprocating mass as low as your budget allows, you will go along way in keeping the motor alive. Less weight....less pounding when the revs go up. Unfortunately the same can not be said for the narrow rings. I personally don't know anyone getting 100K from a narrow ring package. If endurance is your goal, go with the 5/64" ring pack but go with Total Seal Rings and have your machinist follow the instructions to a tee! Of course, do the regular stuff that makes motors last....keep that air filter clean, change your oil every 3K, use sythetic oil after the break-in, and make sure your cooling system is in good shape. Then save up for a dual turbo set-up and catch those Saleens flat-footed !!!!! Seriously though, racersauction.com has several suppliers for light-weight quality small journal rods. Even if you don't feel like bidding, you will be able to get the mail order links for the suppliers and check out what they have available.
If you choose a small journal 327, you will have to go retro-fit on the roller cam set up. Your biggest expense will be the lifters because the cams can be had on ebay for much cheaper than retail. Just have to be patient and find the specs that suit you. I did a roller cam retro for my 400 small block for about $500 including a billet aluminum timing cover and cam button by just being patient. Make sure the roller cam you choose has a cast gear (to run the distributor) pressed on so you don't wear the combination out prematurely. These cams are getting more available from all the major cam manufacturers including GM. Using a bronze distributor gear with a hardened billet cam is a pain! I believe that AFR has Rev-Kits for most retro-fit set-ups.

 

What is the bore dia. of the slot for the flat tappet lifter used on the early model blocks? I was scouting around looking for lightweight lifters and Jesel seams to make a nice tiebar style lifter along with Crower, both companies also offer keyway/ groove-lock style lifters. How light are these lifters compared to the tiebar style lifters, and by what means does the slotted bronze bushing attach to the block. I would assume that these two styles of lifters are classified as solid lifter? What is the rod length I would be looking for with a dished piston, 6.000”? I would like to run 8.5:1 compression; I know the combustion is supposed to take place in the dish of the piston rather the combustion chamber of the cylinder head, so using a set of kidney/ fastburn shape heads, would it be preferred to use a smaller cc head like a 62cc and not bring the TDC of the piston to a zero deck height?

 

Wish i thought of just pinching the tube between the manifold and head at the time... would have saved me alot of effort and precision guesswork, lol.

 

The dipstick was the one thing I hadnt thought of before hand..Had the motor in and was wondering wth I was going to do.. so I just gave it a try.

 

According to Popular Hot Rodding's feature story "Hot New Valvetrains" June 1996, the Crower "Groove Lock is 96 grams. This is compared to a typical link-bar lifter at 116 grams, raised the rpm level in their test small block from 7800 rpm to 8200 rpm. Round up this article, if you can. It gets into testing light-weight valvetrain components and gives actual weight and rpm capability by using the product.

The general thinking on the piston/combustion chamber is flat-top pistons with small combustion chambers. A pop-up piston has disruptive flame travel and the problem increases as rpm goes up. With a 327, you would definetly be looking at 58cc chambers to achieve 9.5:1 compression. AFR has heads already cast at this cc for just this small engine application. I don't know if Vortecs have the deck thickness to go this small.