greywuuf

Well I found my winter porject, and I need to decide which way to run with it.
heres the deal, I have a '72 1/2 ton pickup with a 383 and TBI, and also a 89 RS with a 305 TBI.

I also have a low mile never bored 400 2 bolt block.

I have a serious jones for a ramjet intake and I am wondering if a set of vortec heads will feed a 400? Also which ride do I put my new engine in ?
I live in an emmision inspection state so if it goes into the RS it has to be TBI and will have to apear factory ( qwiky lube doesn't look to hard if it looks right) I think I could almost sneak a ram jet by them except for the EGR... no functional check of the system it just has to be there. The pickup is exempt so if need be I will put it in there. Can I get a factory apearing TBI to work reasonably well on a big inch motor ? Should I swap the 383 into the RS and then do a ramjet on the truck ?


Now to the motor, I figure on installing 4 bolt (splayed) main caps and decent set of heads, other than that I have no rotating assembly and am open to suggestions (have always hung onto this thing in the hopes of building a big stroker) If anyone has practical experience I would love to hear from you.
If I go the ramjet package how does everyone feel about the cam ? I realize it is mild for an engine this big but it makes for a FLAT power band on the HT383

thanks
Dan

acidpad

I'll take a stab at this, but I am by no means an expert.

I am just finishing up building a 406, so I do have a bit of experience. If you look through CHP you will see that they build a 400 with vortech heads and it was a monster. Personally, i stepped up to a set of dart iron eagle plat. 215cc, just because with the big cube engines, they love to breathe.

Splaying the caps to 4 bolts might not be such a good idea (and most likely not even necessary) The reason the 2 bolt blocks were better than the 4 bolt blocks in 400s is due to the lack of material, so the additional 2 bolts, actually make the casting weaker.

Your stock TBI is not going to feed the 400, I wouldnt even waste time thinking about it, either find a way to sneak it by with something other than TBI, or put it in the truck for 3 years until the camaro is a classic.

Another thing I noticed in your profile, the T-5 ..... yeah, 400s are torque monsters. You can baby it and keep the T-5 alive for a while, but you will blow it up. quick.

As far as not having a rotating assembly, I hope your looking at dropping a good amount of money into it. Just for comparison (and mine is all forged), but the final talley on just my rotating assembly comes to ..... ~$1300 and thats just parts, not machining. for a breakdown on that:

Forged crank: $289
Ohio crank H beam rods: $350
Probe forged Pistons: $400
bearings / rings: $200

I'm not sure what the ramjet package is, but I wont touch on that since I dont have experience. I built mine to be carbed for financial reasons. Lets put it like this, i started in a similar position as you, where the only thing i wanted to keep was my block, and built up from there. I already have well over $5k into it, and its not done. If i had it to do over again, I'd buy a crate engine. Sure, building youll feel real good after your done building the engine, and it will outperform anything crate $/hp, but its alot of work, alot of time, and alot of uncertainty. Not trying to stop you from doing it, just letting you know first hand what your getting into.

Re-reading your line on the ramjet, one thing I do want to comment on, if its extreme on a 350, its very mild on a 400, keep that in mind. That and the 400s like to breathe thing, 2 biggest rules I've found on the 400s.

Best of luck to you.

sofakingdom

iTrader: (1)

The extra 2 bolts in the 4-bolt 400 block DO NOT make the block "weaker". What actually happened, was that the early 400 blocks (which all happened to have 4-bolt caps installed on them) had less metal cast into that area; and the later blocks (which all came with 2-bolt caps) had more metal in the casting. It has NOTHING WHATSOEVER to do with the bolts themselves. It's just convenient to identify early vs. late by the highly visible 4-bolt vs. 2-bolt main caps. Somehow, hot-rod parkng-lot lore has warped and magnified that into "4-bolt caps weaken the block". That's not true.

If you leave TBI on it, you don't need 4-bolt main caps. That's an EXPENSIVE mod, by the time you actually get done with it; totally unnecessary in a motor that you've crippled so severely. Basically ZERO bang but LOTS of bucks. On the other hand, if you stroke it and put something on top of it that can breathe, then it becomes a more reasonable thing to do.

You can make a T-5 live behind a 400, or you can tear one up in seconds with a 305.

IMO the RamJet is not a very good choice. It's quite expensive, and requires its own stand-alone computer, unless you do ALOT of re-wiring of your car. Which while not difficult for somebody that knows how to do wiring, is not a trivial matter for most people. (kind of like brain surgery.... might be easy for a brain surgeon, but I don't think you'd want me, for example, cutting on your brain.)

As far as emissions are concerned, what you'd want to do, depends on what they require where you live. Some places don't do a visual AT ALL. Other places just look to see if you appear to have a cat. Others pull out a book that shows every single device, wire, vacuum line, and so forth, and they verify each and every one. Others don't look at anything at all, but just sniff the exhaust. And so on. Before making a decision based on that, be certain you know what's actually required and checked in your locality.

greywuuf

First off, a thank you for the replies, and an apology. I did not state my intentions, or even my thoughts/situation clearly.

I think my questions should have been along these lines:

first:how much more expensive is it to build a stroker 400 than a stocker. How much reliability ( read longevity ) will i expect to lose? the 400's are taking things pretty far to the edge of the original SBC intent to begin with.
dos anyone feel it is "worth it" so to speak. ( let me say that I have always had a fascination with the "magic" 427" but the tall deck in my deuce and a half doesn't really count)

Second: Will vortec heads reasonably support this large of a motor or will they become a huge restriction ? (keeping things sane and well mannered on the street)

third: I understand that power shifting and smokey burnouts are off the table for the T5, but somedayI plan on a t56.... maybe sooner maybe later.

Fourth: I am in my mid 40's and can resist urges (actually don't have them all that often anymore)like that pretty well. I also am not trying to go to school and doing this on fast food wages, I do have a family and have to keep things under some kind of financial control. This is my "mad money" so to speak.

Fifth: I was one of the first group of 50 sate certfied Vehicle Emission inspectors in this Town. I know what is required and what you can "get away" with.

Sixth: I worked all through High School and after as a dealer mechanic but am now ( and have been for years) an aviation electrician and radio guy.


My 72 pickup is running a '92 firebird TBI system (with a few cop car parts and BIN thown in for good measure) and I have researched switching it over to tpi several times, just never went through with it.

I am considering the RJ because I love the look and the flat TQ curve. What I dont know is what level of power the RJ intake manifold will support ?

I guess I am just looking for good advice on what heads to run (vortec or aftermarket) for a 400- 450 HP 400(or larger) SB with a RJ injection system.
Also I am kinda looking for opinions on putting that large a motor in the RS (I am pretty sure with my mill I can come up with a way to bolt an EGR valve onto the manifold as I said it doesn't have to work it just has to look like it belongs there) sooooo..... anyone running a big cube SB with a RJ in a third gen? and recomend some good combo's rotating assembly wise for a decent used 400 block.


thanks
and sorry for being first so vauge and then so long winded
Dan

PS Thank you Sofakingdom you touched on a lot of things I just wish you had known more about me as I think you would be very interesting and informative to discuss this with.