Hey everyone,

I've made several posts over the past month or two regarding my 91 Z28 and the process of pulling out the old 305 TPI motor. And I have been looking and looking for an acceptable crate motor that would upgrade it to a 350 while still keeping the fuel injection system. Granted I know there is a lot of tuning the PROM in my future once swapped, but its been really hard to find a crate motor that is "Fuel Injection" capable. But then I saw that GM made a *new* crate motor and has just started marketing it (as of Aug 1, 2020). Here's a quick link or two:

Link1
Link2

Now it is only talking about being a truck replacement, but the "gen1" version says its good for GM Trucks from '87 - '95 and that tells me it should be TPI friendly because that was the intake used during that generation of motor. It is only sold through dealers but has a 3 year 100k warranty and claims to be new motors... not remanufactured. Any thoughts on this? The only thing I see would be a concern is that it has Vortec heads, so a new intake manifold will have to be used.

 

Upon a little more googling... I think the Engine link (to buy), is here:

https://www.gmperformancemotor.com/parts/12703983.html

Although the picture here shows a 6 bolts for each intake side... so not a Vortec. But it might actually be a better match for my '91 Z28

 

There's no such thing as a "crate" motor that's "fuel injection capable", or not. That's like going to the bicycle store and looking for one that's for a fish, or not. People won't treat you kindly: they'll kinda look at you funny and say something like [banjo music]"ye ain't from round heer are ye booyyy"[/banjo music]

You have TPI. Its unique intake, specifically the BASE of it, puts you in a unique and specific situation.

You DO NOT want a motor for 87-95 trucks. That will have the crappy 191/193 style "swirl-port" heads, which are DEATH to performance (flow). They make good low-end torque, that being what a TRUCK needs, but result in an engine with no whooma-whooma. No breathing, no high RPM capacity AT ALL. You know, (or maybe not) one of those "stoplight wonders" that snaps your head off your shoulders at a stoplight, but takes 2 minutes to pass a semi on a 2-lane road at 55 mph; 0 - 40 in 3 seconds, 40 - 70 in forever-and-a-half, if ever.

The other is a "Vortec" motor; 96-up. Good foundation for a build; terrible cam, but that's easily enough rectified; BUTT: there is ONLY ONE TPI intake "base" in the whole world that will fit it. You can get it from either Scoggin-Dickey (who first marketed it; probably had the design done) and more recently, from Edelbrock. Same part, different source, no idea about pricing but I doubt that's significantly different either.

That last one you posted while I was answering is PURE UNMITIGATED UNVARNISHED UNADULTERED CRAP. It's a mid-70s smogger replica with 993, 882, or 624 heads, or a replica of them; and a flat-tappet 929 replica cam in it. If it was installed in a vehicle with a 4-bbl carb it would be "rated" at 165 HP instead of 210 which doesn't take into account any "accessories" (not things like AC PS alt etc., but rather, EMISSIONS things). That EXACT motor has been keeping cars slow for over 45 years now. THE DUNG.

Choose wisely.

 

OK, the Vortec option isn't so terrible. I quickly looked for the Soggin-Dickey base plate you referred to and I think this is the one you are talking about. In regards to the "terrible CAM" what replacement options exist? I'm not looking for an aggressive cam... just something that might get me close to a 300 HP total without blowing up the engine.

 

TPI is well-known to be picky about cams. It wants a cam that works WITH its "tuned" aspect (the "T" in "TPI"), and doesn't react well to cams that aren't in that mold, even if they're "good" cams in other situations.

This one is a good one to look at. https://www.summitracing.com/parts/cca-08-502-8 As well as its next bigger brother, same part # except with a 3 instead of a 2, although that one will likely need significant tuning, which is not a trivial matter with these old 70s computers. It's not like tuning a LS motor where you can do it all with a laptop. However all that may be, that whole series plays well with TPI's restriction on RPM range. This is another one specifically made to work well with TPI. https://www.summitracing.com/parts/cca-08-304-8, and its next-bigger brother the 305 grind.

 

I should mention, NO MATTER WHAT, a motor with Vortec heads from GM will ABSOLUTELY POSITIVELY UNEQUIVOCALLY need new valve springs. The ones GM puts on those heads are unsuitable in every way for aftermarket cams. If you decide to go that route we can help you get the right springs.

 

Too bad GM can't throw us a bone, with a 350, roller block, 4 bolt main, 1-piece rear main seal, EGR ready, approx. 300 HP new Crate Engine.

 

The one you have linked for sale and the one described in link 2 are quite different. The L31 crate seems to have been discontinued and the one announced may be it's replacement if there is one at all. Where this new crate is for sale and if it's what you're looking for remains to be seen.

 

well if I remember correctly you can take any 350 and change the intake to make it fuel injection which in turn would still need all those things. My memory is shot but I’m trying to think what I did this on before

 

Thanks for the links! I would definitely like to minimize tuning so I'll be avoiding both "big brother" parts. If you have some ideas about springs, I'll gladly take those suggestions. I'm going to call some dealerships this week to see what info they can provide for the "Gen 1e LD covering light-duty trucks Crate Engine". I think that's the Vortec one. At the moment it sounds like I'd be getting that one + new cam + springs and then drop that stuff off at a machine shop to do the swap. Then once that's all put together I can look at doing the intake stuff myself before putting it back into the car.

 

OK then, the 304 is probably the way to go, if you want to keep tuning to a minimum.

Springs: https://www.texas-speed.com/p-1383-l...od-to-550.aspx
Retainers: https://www.summitracing.com/parts/cca-787-16
Keepers: https://www.summitracing.com/parts/cca-648-16
Seals: https://www.summitracing.com/parts/fel-ss72861
Shims: https://www.summitracing.com/parts/cca-4753
Spring compressor: https://www.summitracing.com/parts/otc-4573
Push rods: https://www.texas-speed.com/p-8292-t...set-of-16.aspx probably 7.300" but you may have to measure; if so
Adjustable push rod: https://www.texas-speed.com/p-7372-c...6800-7800.aspx

You'll want to set those springs up for an installed height of 1.75" - 1.8", preferably closer to 1.8". To do that you'll need one of these, along with the shims. May take more than 1 set of shims although probably not, with stock heads it can be REAL hard to know what you're gonna find until you dig into it.
Valve spring mic: https://www.summitracing.com/parts/pro-67390

I would STRONGLY recommend NOT "dropping off at shop". None of this stuff is really particularly had to do. Any shop properly equipped to do it, and that can be trusted to get it RIGHT (it requires a RACING type of "shop", not just yerbasic corner parts store kinda place) will charge you more than the tools to do it yourself will cost. Plus you'll get to enjoy the satisfaction of a job well done.

 

Agree 110% with Sofa...

But I would use these springs (PAC 1218):

https://www.summitracing.com/parts/rsc-pac-1218-16

My Vortec spins up like an LS with these. Honestly people are very surprised how responsive it is. Stock bottom end and stock heads. Just cam and valve train.

GD

 

Thanks for all the links guys!! I really appreciate it. I'll let you know what I find out from the GM dealership about these new crate motors.

 

Curious what, if anything, you found out.