Rebuild opportunity....

[8T6K5]

The TPI350 is definately due for a rebuild, plus due for emissions in 2mos. Not sure how thats gonna go, so Ive been looking for awhile at my options.

1) Rebuild TPI350
2) Crate motor
3) Find core to rebuild.

Would definately opt for a 383 if at all possible, but then found this.....

...400cid SBC from a 70's El Camino. Obviously needs a rebuild, oil pan-intake, but for $150

.....still need to inspect it and ask a few more questions, but what says C5KB?

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Worst case I get a block for $150 to use as a core.

 

[crazy4offroad]

No replacement for displacement, I vote GO FOR IT!

 

[Green79Scottsdale]

If the block is still good to clean up the bore, DO IT! 406ci under a TPI sounds like a tug boat motor. Build it while keeping the 350 going, then when it is ready swap it out in a weekend. Can probably run a bigger cam with the extra cubes. I wish I could get a 400 around here for that price. People think they are made out of gold around here.

 

[8T6K5]

If the block is still good to clean up the bore, DO IT! 406ci under a TPI sounds like a tug boat motor. Build it while keeping the 350 going, then when it is ready swap it out in a weekend. Can probably run a bigger cam with the extra cubes. I wish I could get a 400 around here for that price. People think they are made out of gold around here.

Thats the plan, more like a 3-6mo plan. Dunno about the 406 just yet, depends on how clean everything is, not opposed to it though. 377?

Not planing on keeping the TPI, that would just add $$ by needing a new intake and larger tb-runners-injectors to really make it work. Homework says go with a Holley 750cfm

 

[Jims86]

Thats the plan, more like a 3-6mo plan. Dunno about the 406 just yet, depends on how clean everything is, not opposed to it though. 377?

Not planing on keeping the TPI, that would just add $$ by needing a new intake and larger tb-runners-injectors to really make it work. Homework says go with a Holley 750cfm

Wont need a new intake or larger runners, unless you plane on trying to race Camaro's.
the center intake bolts would be the only obstical, but I personally would freshen up those L98 heads, and use them on the 400, then its all go, save for some chip tuning...And You can join Gearhead EFI for that Hookup.
I think ther may already be a TPI 400 tune running around already.

 

[8T6K5]

Wont need a new intake or larger runners, unless you plane on trying to race Camaro's.

Pretty sure I will on the intake. Vortec heads are direct bolt on to L98, but require aftermarket intake to keep TPI. Should be the same across the board? Runners, maybe not, but 52mm TB and injectors yes. Cost: $1000est. Roughly more than 2X amount for new carb, if TPI intake is needed add another $400.

If I can sell the TPI for $400 (avg on CL here is $500+), plus savings by going to carb, theres my tranny rebuild.

Race Camaros? Ill leave that to the K1300S

...but I personally would freshen up those L98 heads, and use them on the 400, then its all go, save for some chip tuning...And You can join Gearhead EFI for that Hookup.
I think ther may already be a TPI 400 tune running around already.

Hadnt even considered that; considering the heads are usualy the first thing to get replaced on the L98, in lieu of some Vortec heads. L98's rated at about 275hp and the biggest complaint there are teh heads. Why put them on a larger ci motor?

Been reading about needing "steam ports" on the 400 heads for bigger hp set ups, 400+. Not sure I need that much hp, not sure my tranny wants that much. back to the TPI dilema.

 

[bucket]

Pretty sure I will on the intake. Vortec heads are direct bolt on to L98, but require aftermarket intake to keep TPI. Should be the same across the board? Runners, maybe not, but 52mm TB and injectors yes. Cost: $1000est. Roughly more than 2X amount for new carb, if TPI intake is needed add another $400.

If I can sell the TPI for $400 (avg on CL here is $500+), plus savings by going to carb, theres my tranny rebuild.

Race Camaros? Ill leave that to the K1300S



Hadnt even considered that; considering the heads are usualy the first thing to get replaced on the L98, in lieu of some Vortec heads. L98's rated at about 275hp and the biggest complaint there are teh heads. Why put them on a larger ci motor?

Been reading about needing "steam ports" on the 400 heads for bigger hp set ups, 400+. Not sure I need that much hp, not sure my tranny wants that much. back to the TPI dilema.

You need the steam holes because of the siamesed cylinders. You can drill them yourself using a 400 head gasket as a template.

You only need an intake if you go with vortec heads. True, the stock intake and runners cannot support the flow a 400 needs for peak HP, but peak HP is not your goal. You will still have tons of low end grunt that you do want. The stock TB will support a lot of power. Might need bigger injectors though, what do you think Jim?

 

[Jims86]

You need the steam holes because of the siamesed cylinders. You can drill them yourself using a 400 head gasket as a template.

You only need an intake if you go with vortec heads. True, the stock intake and runners cannot support the flow a 400 needs for peak HP, but peak HP is not your goal. You will still have tons of low end grunt that you do want. The stock TB will support a lot of power. Might need bigger injectors though, what do you think Jim?

He could get away with 24pph injectors, and the tune is simple, all he will need is a way to Datalog, and thats just a $30 ALDL cable, and a free copy of tunerpro RT.
As far as complaints about L98 Heads, those complaints are coming from Camaro and Corvette owners...especially those whom have gotten a taste of the LT1, and then an LSx powered car.
I have NEVER heard on complaint from a truck owner equipped withnan L98, unless he left the L98 stock Camaro cam in it. That cam is meant for3300lb car, with MUCH better aerodynamics.
The Heads are Extremely sought after by gen1 SBC powered truck owners.
And as far as cams go, the HT383E roller cam is a monster in the L98.
Thats same combo under a 750 cfm carb isnt too shabby either, If you wanted to sell the TPI for a trans rebuild.

 

[8T6K5]

Great information, thanks guys.


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[Green79Scottsdale]

Thats the plan, more like a 3-6mo plan. Dunno about the 406 just yet, depends on how clean everything is, not opposed to it though. 377?

If you get the 400, 406ci is simply an overbore, .030 over I believe. You have everything for a 406, don't go backwards to 377. Didn't see it addressed so I thought I would throw it out there.

 

[8T6K5]

You only need an intake if you go with vortec heads. True, the stock intake and runners cannot support the flow a 400 needs for peak HP, but peak HP is not your goal. You will still have tons of low end grunt that you do want. The stock TB will support a lot of power. Might need bigger injectors though, what do you think Jim?

Pretty much coincides with what I have been reading the past day or two. Posts from other forums are 50/50 on keeping the TPI with a 400 or not. Based upon what Ive read, it sounds like a great set-up for a truck-not so much for a Camaro.

As far as complaints about L98 Heads, those complaints are coming from Camaro and Corvette owners...especially those whom have gotten a taste of the LT1, and then an LSx powered car.
I have NEVER heard on complaint from a truck owner equipped withnan L98, unless he left the L98 stock Camaro cam in it. That cam is meant for3300lb car, with MUCH better aerodynamics. The Heads are Extremely sought after by gen1 SBC powered truck owners. And as far as cams go, the HT383E roller cam is a monster in the L98.

Still havent found any info on the L98 heads on a 400, still have lots more looking to do. Aside from the steam ports, looks like there will be some other work to be done and rebuilt. Need to compare that to a new set off the rack.

As far as cams go, may opt for a smaller torquey cam? They say the TPI runs put of breath around 4500rpm, why get a cam with a curve up to 5500?

 

[SlickGTP]

Hell, the carb and intake on that motor are worth more than the $150... For that kind of money I'd pick it up.

 

[bucket]

As far as cams go, may opt for a smaller torquey cam? They say the TPI runs put of breath around 4500rpm, why get a cam with a curve up to 5500?

Yes, they do start running out of breath up top, but some guys make it seem worse than it actually is. The power starts to fall off, but it does not go away. If you pick a cam that is too mild, you will end up with stump-pulling torque when you are just idling and losing potential mid range. Figure out about what your current stall speed is and then pick a cam that comes in just before that stall speed. If the listed powerband for that cam is higher than 4500 or so, big deal. This should give you some wiggle room since the stall will probably be a little higher with a more powerful engine. And remember, an aggressive cam in a 350 is going to be a little more mild in a 400.

 

[Jims86]

Pretty much coincides with what I have been reading the past day or two. Posts from other forums are 50/50 on keeping the TPI with a 400 or not. Based upon what Ive read, it sounds like a great set-up for a truck-not so much for a Camaro.



Still havent found any info on the L98 heads on a 400, still have lots more looking to do. Aside from the steam ports, looks like there will be some other work to be done and rebuilt. Need to compare that to a new set off the rack.

As far as cams go, may opt for a smaller torquey cam? They say the TPI runs put of breath around 4500rpm, why get a cam with a curve up to 5500?

Yes, TPI is very nice on the trucks, GM missed the train on that one.
As far as cam, The HT383E is a very torquey Alternative Truck Replacement engine for the 350 Vortec. The cam in that engine has a pretty short duration, 196 int, and 206 exh@ .050 lift is 431/451 resp.
Hyd. roller tappet.
As far as the heads...other than drilling steam ports, there really should not be any other issues, althought you may want to do some light porting.
And a Chip tune to top it all off, you should be a happy camper.

 

[8T6K5]

Sounds good. Ive gotten a lot of my TPI info from a Camaro forum I peak in once and awhile when I have motor Q's. I guess Im not really comparing Apples to Apples if the 400 is going in a 1/2T truck.

Good news is that I got the casting #330817. Shows to be the 2 bolt w/4 freeze plugs as opposed to the 4 bolt w/3 freeze plugs. The 2 bolts seem to be the preferred block of the two.